Guys,
S100 is a cleaner, and it repels dirt residues.
http://www.s100.com/s100_tcc.htm
it comes in a variety of packs - I have always used the 500ml bottle sprayer, either sprayed direct or wiped on with a sponge if the grime is thick.
Hose it off with a medium pressure spray gun (namely a cheap Karcher set on fan spray)
The 500ml bottle used to cost about $30 and lasted a year on a bike.
Cant speak highly enough of it.