Record Cleaner Advice?

I use a Monks-- the traditional model than relies on a thread to act as a buffer between the point nozzle and the record surface. (It is one of the newer models that was introduced after Keith’s son rebooted the company and is called the "Omni"). I also use ultrasonic. The combination of cleaning methods is synergistic in my estimation.
I have not had any "hands-on" with the newer, less expensive Monks design that dispenses with the thread altogether.
Frankly, most of the results obtained from vacuum type RCMs are based on method rather than the machine itself (although I prefer the point nozzle type to the wand type vacuum cleaner for several reasons).
I can get very good results using an old VPI with a good cleaning fluid, rinse, and using separate applicators and vacuum wands for the cleaning and rinse steps. I’ve done back to back comparisons using the old VPI (which is still sold) against the Monks, and for most purposes, I suspect the VPI would be fine at a fraction of the cost of the Monks Omni.
As to questions and concerns regarding ultrasonic, I suppose you must be the judge of that for your own record collection-- I have cleaned thousands of records in my own collection using ultrasonic in combination with vacuum and have experienced no instances of damage, deterioration of sound quality or any of the other potential hazards raised about the risk of ultrasonic cleaning. I’ve owned the Audio Desk and the KL and when the KL dies, will go DIY (with a caveat noted below).
At the end of the day, your objective is to get the record clean and leave no residue of cleaning fluid or other contaminants. This is another reason why method is more important to me than the particular machinery involved. There is merit in DIY ultrasonic, which doesn’t require enormous skill; many go this route for cost-effectiveness. To me, the DIY route would be an avenue for additional features and functionality not found on the commercial made for LP US machines currently on the market and likely cost more than the commercial LP cleaning machines. Obviously, the first commandment applies here: do no harm.

@billstevenson -that paper, written by Neil Antin, seems almost overwhelming at first but Neil does an excellent job of methodically explaining not only what he is doing, but why. Neil was responsible for the cleaning protocols of oxygen systems on submarines as part of NAVSEA and dealt with life-critical systems. He knows the chemistry, and has methods to evaluate effectiveness, including whether any residue of cleaning agent remains (which is regarded as a contaminant). 
I think Neil is registered to Audiogon, so can be reached to answer questions. Disclaimer: I published the paper (which was an honor to do so).
Bill Hart

@antinn did a good job of summarizing what is available as a "one button" type pop in the record and walk away type ultrasonic. @keegiam- you are astute enough to appreciate that the ultrasonic cleaning is not a complete solution and if you are buying used records (not necessary bargain bin/Goodwill sourced cast-offs), you may need to resort to manual cleaning (in combination with ultrasonic). The high cost of made for LP ultrasonics is what drove people to the DIY camp- which was, as far as I know, already involved in ultrasonic cleaning of LPs before the Audio Desk was first commercialized.
I think most of us experiment a bit, and based on results, find a method or series of methods that is effective and meets the needs of the user for both efficiency and cost.
Although the Monks was around circa 1970, and the VPI and Nitty Gritty came to market in 1981 if memory serves, my take is that it was only after the Death of Vinyl™ that people really began using RCMs more broadly since they were buying used records, including a lot of the audiophile stuff recommended by HP, Sid Marks and others (older RCA dogs, Mercury Living Presence, Decca, etc).
I honestly don’t know why I got sucked into the record cleaning area as a subject of interest. I had arranged to visit the intake facility of the Library of Congress located in Culpeper, Va. mainly to talk to them about cleaning, but the archives, old equipment, new technologies to read fragile media and the shelves of material on deposit and awaiting intake and accessioning fascinated me. I eventually published a piece on that visit which was one of the first of many on the topic (the recording cleaning part was really subordinate to story of the facility itself, but later installments on record cleaning followed).

@lxgreen - your response raises a number of good issues, none of which are confined to the Nitty Gritty machine. One is multiple cleaning methods and steps, which I have found to be synergistic. Despite your delight with the results of the Degritter, you may want to keep your Nitty Gritty around as a pre-cleaner for records that aren’t effectively cleaned with an ultrasonic process.
The other issue is whether you want to use a surfactant as part of the ultrasonic cleaning process. We are told (and have seen photos showing) that the surfactant in the bath enhances the cavitation process by lowering the surface tension of the bath water.
The question then becomes how one effectively removes the residue of that surfactant in completing the cleaning process. Forced air drying will not do so; I had that experience when I owned the AD and could see how records cleaned with it exhibited a different behavior when wetted than a record that had not been run through the AD.
This suggested to me that some surfactant remained on the record surface, though frankly, I never heard a sonic signature from it. (I used little more than a capful of the AD fluid, rather than a whole bottle, based on comments from some early adopters).

I know the Degritter allows you to change out water containers which means you could conceivably clean with a surfactant, then change the water "cartridge" to a "pure" water container for a rinse cycle-- but that "pure" water bath is going to get polluted pretty quickly with surfactant residue.
Distilled water is certainly cheap enough in the States to enable you to change out the water constantly, but you’d probably have to clean the inner walls of that container (and Lord knows what the innards involve in terms of removing any surfactant traces from the inside of the machine itself).
Am I being a bit anal about this? Sure. One solution is to finish the record using pure water and a vacuum process, but the Nitty Gritty may not be conducive to that.
I also wonder if not doing a "pure" water rinse step when you were using only the Nitty Gritty resulted in less than satisfactory results- that is, there was residue of the cleaning solution along with other contaminants (that you were trying to remove) that were still bound to the record surface.
Good luck with your Degritter- in the current market, that seems like the unit to go for "one button" LP cleaning. I’ve only heard good things about the unit, including from @albertporter, a longtime Audiogon member who has owned and used virtually every high end RCM.
I’m still thinking of a design for an industrial level ultrasonic that might accomplish it all for less than 10k Dollars. :) In the meantime, we soldier on.
Bill Hart

Neil- I didn’t think it was actually pigment but it is very fine and stains. See the thread you are in on Hoffman re the Degritter, Neil, where Phil describes it that way. What’s interesting is this-- it only happens with new records that have not be precleaned. If I preclean a record it doesn’t seem to appear in the US reservoir. It must dissolve too, because if I preclean it’s on the Monks which has a clear glass jar (almost like a British mason jar with a metal lid and a couple of barb type fittings for hoses). The waste water will be cloudy after any kind of clean but not dark or show evidence of the stuff as grit (I like examining the entrails of what comes off the record- very Druid).
Tim- it’s too bad the KL is no longer but mine is still (knock wood) running ok and I like the machine. I’ve been kicking around ideas about an industrial approach to this with Neil for the next machine but we haven’t gotten into detail yet.

Tim, you can access the reservoir tank on the KL through a screw off port on the back. It has sharp edges (as one learns the first time) and isn't easy to align the threads to get back on properly seated. That said, it does not allow you to access the actual bath where the water and record meet. 
I use clean room wipes to wipe down the inner walls of the reservoir, using rubber tipped oversized tweezers to hold the wipes. What it shows is nothing if the records have been pre-cleaned on the Monks; if a new records goes directly into the KL, there will be a very fine black grit, almost like pigment (a term someone else used to describe this on another forum). Neil has a second edition in the works. It's gonna be good! 

@antinn -- you didn't tell everybody about the 2nd Edition? That expands on the chemistry, covers stuff that isn't available in the UK/EU and does a deep dive into ultrasonic chemistry and processes? You know, this one: [url]https://thevinylpress.com/precision-aqueous-cleaning-of-vinyl-records-2nd-edition/