Coming back from a ride around the great lakes last summer, I had so many bugs, it was hard to tell what color the fairing was!
I also use the wet towel trick. Wet a couple of big bath towels, and lay them over for 1/2 hour or so to rehydrate the little buggers. At this point, I avoid rubbing, as some of these criters have some hard shells, so I use the water hose nozzel to get off as much as possible. That usually gets all of the hard parts. I then coat the area with S100, and let that sit for anotheer 15 minutes or so, then rinse and scrub with a micro-fiber wash mit.
I will say it does help a lot to hit them as soon as possible, but after a 7 day ride, this routine works pretty well. I also make sure to put on a nice coating of wax prior to leaving.