I like John's idea.

I've been having the same problem and what I noticed the last time I took the cover off (using a solar reel on a 24' AG pool) is that when I get to the last third or so, there is a lot of debris on top of the cover that would normally fall into the water when the end comes up so if I get the hand skimmer at that point and scoop out as much of that as possible, that should help reduce the amount of stuff going into the pool. Combine that with John's idea of hosing the cover off first and that might be as good as it gets.

Peter