CT18 or CT20 truck wash, water a sponge and a hose.
Don't get your air filter wet, plastic bag and a garbage tie work's well, and if using a pressure cleaner try not to hit any area's with bearing's if you can.
Dry the bike off as best you can, used compressed air and a blower if you have one.
You should buy some dielectric / bulb grease and smear it in/on all the electrical connection's on the engine/loom, kill to loom, coil to loom, cdi to loom, coil to frame, loom earth to frame etc etc to stop corrosion from forming and causing headache's later on
Spray any area's you think are likely to corrode with some wd40 or inox but stay away from your brake's obviously.