Does LAST Preservative DULL sound?

Got one cautionary message from another respondent via email that LAST Preservative could ruin Lp's leaving a "dulling effect".All I knew was I tried it and have been happy after head tech at VPI told me he wouldn't live without it.Said he'd have people who brought LP's to him at shows that they had treated since new with LAST.He said one should clean LP first to remove chemicals used by by LP manufacturers as reslesing compounds.At these show he'd spin the LP's and would inquire how many times it had been played and many replied "hundreds" whereas to his ears (because of the LAST Preservative)his guess was maybe half a dozen.So here was a reccomendation from somebody you'd expect to be "in the know" with no interest fincailly or other wise reccomnding anothers product.So even though I have heard many positive comments about LAST's Preservative even from folks wo use Disc Doctor cleaner or another "power"(pre) cleaner or like myself who use home brew(with alchohol which is another debated aspect of Lp care- does it "dry" LP's or leach out platcizers etc) but would like to hear if anybody else has found this very expensive product to harm the sound of LP's.I myself have not experienced it (using both their Power Cleaner and Preservative plus my homebrew which I was off with a second clean with hot water before applying the Preservative.But I know dulling could be a posibility with everything except purified water.I myself used Touramat on scratched LP's and it acted as a "lubricant" which in fact made clicks and noise less obstrusive.Comments on LAST products especially the Presevative,especially if you concur that it can harm,wel I'd really like to hear from you as would others who are "true believers".Think after my Vaccuum machine the LAST Presrvative is the one thing I couldn't subistute or make changes with so was as you can imagine taken aback by this individuals cautionary tale.
As ever (with improved spell checking it is hoped)
This is a typical problem for successful products in the Audiophile culture.
Anything that gets rave reviews, consistently, will attract the "Guru Rejection" group.
This means some folks who consider themselves "Gurus" of Audiophillia will naysay it, just to show that they are above the mundane crowd.
So... Out of the blue, after hundreds of testimonials praising a product, suddenly strange messages like this posting appear... wondering if the product perhaps does something BAD in some mysterious way.
I am not knocking the person who posted the query about LAST! I just wanted to mention the odd way this arises in products that have a long term acceptance and are still praised after years of use.
Personally i would not worry about it. If you can't hear a problem, and some folks you really trust say it is not a problem, then the naysayer can be pretty safely ignored.
my $0.02
Nice response, Elizabeth. FWIW, from my experience, the stuff works, I recommend it.
I can say that it does not appear to have any long-term adverse effects. I've been using it since it was introduced. No records show any signs of wear, the stuff is not sticky so it won't cause problems with holding dust, etc.

I do clean all records, particularly brand new records, very thoroughly before applying the last. I also buff the record quite a bit more than recommended, because the product does leave a few visual markers (dull blotches on the run-out area) if the record is not thoroughly buffed.

After application, the record feels smoother and there is obviously less friction when a brush is passed over the record. Static buildup is also significantly reduced.

The big negative is cost. I buy it in the big bottle ($160), which makes it significantly cheaper on a per once basis, but it still is quite expensive.
I will not comment on the effects of the LAST products because I do not use them. I would like to say that the argument that the LAST treatment reduces the "openness" of the sound of vinyl and "smooths over detail" have been around for many years. I also know people who swear by LAST and treat all their vinyl.
Some "tweaks" have no effect, some have obvious effects but no always positive. Then there are the ones that seem to make subtle differences and there is a divide in opinion on the merits of the changes. This seems to be one of the latter.
The opinion that this may be the typical reaction of the "tweak police" may be valid. It may be the case that LAST has beneficial effects of protecting vinyl at the expense of a slight reduction in high frequency information. I dont know. Whatever your opinion is on the product, remember this debate is not new, and as they say "dont kill the messenger".
While I no longer use it (for various reasons, mostly due to cost and convenience, and the fact that I now have a RCM), all of the records I treated with in almost 20 years ago sound great.
(In fact, becasue of this, I have seriously been thinking of starting to use it again.)

My two cents worth.
I still use it on lp's that I expect to play a lot, say 8 or 10 times a year. But I'm very careful with it, and only apply it while outside the house - for reasons stated below. As far as a sonic signature - I don't hear any difference that could not be attributed to an overactive imagination.

However, the effect I would worry about is your health. I am not aware of the EXACT formulation - but I know that LAST is basically a "Flourinated Hydrocarbon" such as PFOS or PFOA which they originally sourced from 3M. (3M shut down production in 2002 over health liability concerns). It's contact basically turns the top few molecules of the LP surface into Teflon, which to oversimplify - is created by exposing Nylon (which includes viNYL) to a Fluorinated Hydrocarbon gas. Your new Teflon record is much slipperier and heat resistant then before, so it doesn't wear out. However:

Here's a quote from this website:

"The U.S. EPA peremptorily forced one member of this family off the market in 2000: PFOS, the active ingredient used for decades in the original formulation of 3M’s popular Scotchgard stain and water repellent. Shortly thereafter, 3M also stopped manufacture of a related perfluorochemical, called PFOA, that is now under intense regulatory pressure at EPA. 3M formerly sold PFOA to DuPont, which has used PFOA for half a century in the manufacture of Teflon. (DuPont now makes the chemical itself at a new facility in North Carolina.)"

Here's a quote from the EPA:

"PFOS accumulates to a high degree in humans and animals. It has an estimated half-life of 4 years in humans. It thus appears to combine persistence, bioaccumulation, and toxicity properties to an extraordinary degree."
- May 16, 2000. Phaseout of PFOS. Charles Auer, USEPA, Director, Chemical Control Division Office of Pollution Prevention and Toxics (OPPT)

Hope I'm not depressing anyone - my knowledge of this is incomplete, so it might be nice if someone from the Last Factory could clarify the risks. But I'm worried that a full disclosure wouldn't quite be in their interests.
While I have used it, and do seem to like it, I don't seem to notice any severe detriment to using it.
Only thing I've ever seen after using it, was more noticable build-up of crud on my Stylus.

I would assume it acts as a lubricant, and maybe helps keep temps down at the LP's groove? Or so they say it does.

One still has to consider though, the battle of a Stylus that is 10 on the Moh's hardness scale, and exerting a force of perhaps 11 tons per square inch pressure, versus an LP which is less than 1, and wonder just how much can the Last Preservative be expected to defend those precious, delicate grooves? mark
To Markd51's point, there have been some comments in various forums before about certain cartridge manufacturers not recommending it because "crud" could build up on the stylus, and over time, sully the cartridge internals. I believe that was mentioned on a thread here or on AA, but I do not know if it is still in existence. For what it's worth, I still use it and have not noticed any impact to cartridge performance. I just take the time to clean my stylus regularly.