I think I may have cracked the technique to get the best out of a Knosti record cleaner. The thing to do is forget it. .... well that's how I worked it out. I cleaned a batch of records and forgot them, leaving them in the stand over night. The result was a much better clean.
I think leaving them for a couple of hours may allow the fluid to fully drain off the record, taking the grim with it.
I don't think you have to leave the records drying in the rack over night to get this effect, but a couple of hours seems to give much better results than the 7 minutes prescribed in the instructions.