When I got back into vinyl a few years ago (and so glad I did) I broke down and purchased a Vevor 6L ultrasonic cleaning machine directly from them on sale Less then $200 and we’ll worth it! Years ago I had the upper level Nitty Gritty machines and they were good but don’t get that deep down dirt. The ultrasonic cleaners really work great to get the deep down dirt that is in used records and great to have around to just re-clean a record from time to time. I use (after reading tons of forums) a mixture of distilled water, few drops of photoflo solution, a little alcohol and a couple drops of dish washing soap. Then use a waterproof label protector and rinse the record in tepid (not hot) water. Then let them dry. Seems to work fantastic! I’ve purchased VG and VG+ records cheap that had a little surface noise, cleaned them and they were much quieter and very listenable. Brought some up to EX quality.
These cheaper machines only do 40kHz and it would be great to have a 60kHz machine but it still works great. I know the expensive machines will do an even better job but $2k, $3K or even $4k isn’t in most peoples budget. So for a couple hundred you can get a very good cleaning system. Then read the forums to figure out what fluid mixture you want to use. Distilled water is cheep. Buy a small “eye dropper” bottle to hold the photoflo solution and some ultra soft towels (like car polishing rags) to handle the records with. Some people don’t want to use the alcohol but if you do get the 91% stuff. I only use about 1/2 a cup per tank of water and about 3-5 drops of photoflo and 2 drops of dish washer soap. Everyone has there opinion of what to use. Some people just use the water and will freak at my mixture. Others go even further. If you do use alcohol or a mixture like I do you should rinse the records under the facet. This is inexpensive and really brings records back to life. If you’ve got thousands of records maybe invest in an expensive more convenient system.