I use the windshield washer fluid/Dawn/Alcohol mix to clean my planes with as well. I've been using it almost since I started to fly. It's cheap and does a good job cleaning the plane off.

I met with the guys from Epo-grip at Top Gun and they have a new product out that is for cleaning planes. They gave some to try out but I haven't had a chance to yet. I'm on my way to Joe Nall, but hopefully when I get back I'll have a chance to try their cleaner out.

Ken