I use L'Art Du Son Vinyl Record Cleaning Fluid. Sounds French but it's made in Germany. Best stuff I've ever used on my VPI 16.5 RCM.
My process;
1. Soak Disc Doctor brush with fluid and get the spinning vinyl completely wet with solution.
2. Turn off rotation. Clean like Disc Doctor's instruction. 1/3 revolution back & forth with DD brush, 3X, until record is completed brushed & sudsy.
3. Turn on rotation, hold brush steady removing most of sudsy-ness.
4. Turn on vacuum for precisely 2 rotations, no more.
I spoke with Dr. Duane from Disc Doctor & being a chemist guru, he said the soak time is very important as well as the sudsy-ness...
Talking about "Cuckoo for Cocoa Puffs" here... but the above does work very effectively for me...
My $0.02,
Pete