Which cleaning solution do you use in you RCM?

I agree with Topo and Axel's mix. I even go a little stronger, but it leaves things a little "squeaky". (Is bright clean? I don't know) I also use Audio Intelligent, which, being enzyme based, makes me think it's a little cleaner, as it's getting to release agents and other possible organic stuff like fungus. AI is clearly smoother sounding. No, I don't have my system in a room where fungus is growing...

One of these cleaners is more correct. I don't know which. They definitely sound different. I do know which one costs more: ) Photoflo actually put a warning on its bottle years ago not to use it as a surfactant for anything but photos. I've used it for years and have a pretty nice front end: things still sound great on my analogue stuff. I think I would know from years of use if I were doing any harm to my albums.

Hell, I even use Torumat, which has some sort of lubricant in it. George of Stanalog and AJVDH give a wink and a nod to Torumat. It wins the static contest over my other two cleaners: far fewer static issues and records stay clean while they play, instead of attracting dust with every rotation.

Nobody that I'm aware of has done a significant study on the use of alcohol based cleaners: we know they strip vinyl stabilizers, but no one has agreed at what % and at what rate and therefore, how much is too much.

Labratory grade alcohol? No, I use Everclear 20%, 80% triple distilled ionized water and 2 drops photoflow per 8 ounces. If I'm not using near 100% alcohol, then I want to know what adulterants it has in it. Everclear is pretty free of extra "stuff".

With any alcohol, I have never gone stronger than 1/5 by volume, esp. if I were driving;)

Window Cleaning fluid from my car.
Works well and is cheap

I agree with Rushton and I add MoFi enzyme to the list as a second when I am in a hurry or on new. The walker is a time consuming process but does a great job. I just get some headphones and listen while I scrub and 10 or so records to make the mixing worth while.

I love the Audio Intelligent the best so far, over RRL and MOFI. It's just made my records quieter. Can't comment on the static factor. I use the #15 and then their water rinse. They do have a 3 step, but that and the Walker 4 step would prevent me from cleaning at all.
One thing, do not put anything in your path that prevents you from using your RCM, or table for that matter. I learned that from the great Gene Rubin years ago.

Compared to my experience with Audio Intelligent,Disc Doctor & VPI fluids, Walker Prelude is best by a very noticeable degree. I hear improvements on LPs that were cleaned with AI. Also, I find that Walker Prelude is fast, even though there are 4 steps. Each step is fast. With AI, I had to leave the enzymatic solution on far longer to get it to be effective. I am no scientist, but perhaps there is merit to the idea of mixing the enzyme powder w/water fresh each time you use it, as I do now with Walker Prelude. Cheers,
Spencer