I don't wait to dry to see if I got all the dirt. You can tell by looking at the ONR on the panel. If it looks dingy go over it again with the wash. If it just looks like water, you're set to dry. Yes the water in the bucket gets dirty, but the big stuff is on the bottom and the floating stuff is buffered by the ONR. Just don't drag your towel on the bottom and keep turning it to a clean side. This is the way it was intended to be used. I would probably just use a bunch of clean towels and never dunk them back in the solution rather than walk back and forth to those buckets fifty times. I like one bucket and keeping where I am. I have tried it both ways and I don't marr either way, so I opt for the timesaver. 2BM is killer for washing with a boars hair brush because it releases so easy and it's easy to drag across the GG but for rinseless with MF it's just not necessary.