LP Cleaning

I use this guy and I am very happy with the results. Bonus is the price!

https://squeakycleanvinyl.com/products/squeakycleanvinyl-mk-iii

This guy gives some very practical advice and best practices for using the super affordable Spin Clean that reubent mentioned above:

https://www.youtube.com/watch?v=Z3u4_TO9P0M&list=LLaUBqzs6Damc7FLgB3ar56g&index=8&t=5s

My suggestion is that you find a service that has various cleaning methods and if you have duplicate copies of the same record that are in generally the same condition and play equally well, let the service clean with a couple different methods and you can evaluate on your system. Of course, each record may have been exposed to different types and degrees of contamination, but if they are records that you have owned since new, and are in generally good condition, that’s one "test." Another might be a few records that have noise or other sonic gremlins that you subject to different cleaning processes-- same caveat, but the results may reveal something about the different processes that you notice on your system. Finally, such services offer a fully monty cleaning, usually combining ultrasonic and more conventional cleaning. Worth trying that as well.
You can go as cheap or as crazy as you want. My experience has been that there is as much to method, good practices and rinse step as there is to fancy machines. I like ultrasonic, both for its cleaning effect as well as convenience (in the case of the plop it in and let the machine do all the work), but I don’t find it to be a complete answer if you have older, challenged records bought in the ’used’ market. Some audiophiles have abandoned conventional vacuum cleaning altogether in favor of ultrasonic, and there are now cheaper points of entry, including DIY (which doesn’t require that much skill- mainly adding a rotisserie and building a modestly priced filtration unit. The best results i have had come from combining methods).
Thanks for the kind words, @inna-- I would never claim to ’know everything- but have learned a lot just by experimenting, reading, comparing results and discussing with a number of people. Always more to learn. I have concluded:
There is no killer app -- you can get great results without spending a ton of money if you observe some best practices;
a pure water rinse of some sort helps remove fluid/contaminant residue;
no amount of cleaning will help some records. Each LP is sui generis.
A lot of improvement can be achieved by dialing your record player in, being scrupulous in keeping the stylus clean, handling of records, minimization of static, resleeving, etc.
PS: a bad cleaning is worse than no cleaning at all. 

My okki nokki mk2 works well for me.

Cleaning records per se doesn’t extend their life, playing dirty records will shorten their sonic excellence. Why not just clean them as you play them? Clean 5 at a time. That way you are just cleaning the ones you listen to.

A thorough manual cleaning will be as good as any machine. It just takes more time. After experimenting with cleaning and playback I’ve learned that you are really only cleaning the surface and the first 1/3rd of the groove depth. Brush fibers are just not fine enough to get down to the area of the groove that really matters- I’ve measured them. The only cleaning machine that really makes a noticeable improvement in removing unwanted contaminents is the ultrasonic method. It’s a very expensive investment but the energy released by the micro-bubbles does seem to clean deeper than all the agitation-type machines.

That said, I do use an approach that is controversial, but it works for me. I have a second turntable I use just for quieting records that a normal manual cleaning won’t. It’s a decent mid-fi deck with an average cartridge- nothing I care too much about sonically, because I’m not playing my records on it- I’m just using it as my last step in the cleaning process.

After the record is wet cleaned and the surface looks dry, 2 minutes tops, I play the record on the “digger” turntable. Once on each side. This really removes deep, damp crud and quiets a stubborn pressing.

You need to keep your eye on the stylus and be prepared to clean it a few times/side as it can build up with crud pretty quickly.

You will also need to use a wetting agent such a Photo-Flo or similiar to break the surface tension of the water in the cleaning mix. The wetting agent allows the water to get deeper into the groove.

The cleaning brushes with replaceable pads from the Needle Doctor work great.

The final rinse should be just distilled water and a (dedicated rinse-only) cleaning brush to get the rinse down into the grooves.

A final recc: don’t use micro-fiber cloths to clean or dry your records, the fine fibers easily break off and get lodged in the grooves adding noise. Just let them air dry.