For those still interested, I found a review of cleaning materials in the Sep 2003 edition of "The Aviation Consumer".  The final conclusion was that the best cleaner for fuel and exhaust stains, and bugs was Crazy Clean from Sprayway Inc at $3.47 for a spray can, which can be found in Ace Hardware Stores, or by phoning 1-80262-0090.  Apparently it beat the hell out of all the specialist cleaners.  The quote was, "The overall winner in our opinion is Crazy Clean.  A $3.50 15 ounce can of aerosol cleaner isn't an economical way to clean the whole airplane, but the stuff will remove fuel and exhaust stains, bugs, mud, grime and the environmental slime that coats airplane surfaces".

The "environmental slime" sounds pretty nasty.

Jerry Fisher