Ok, ok! I like your method of a pump up sprayer to minimize water intrusion. A gentle spray from a garden hose is ok but I would never use a pressure washer / jet spray on the motor (although I know many do with fine results).
I've used some degreaser on my motors (Griot's Garage, Super Clean, Gunk) when the bodywork or rear wheel is completely off to get a good, clean baseline (mainly on the inside of the swingarm and back and under side of motor, the greasy places). Some degreaser and agitate with a brush, rinse and wipe dry.
My go to maintenance procedure is to use a microfiber cloth and the Pro Honda Spray Cleaner. It's a do it all product that I use on my wheels, too. I usually just spray some on the microfiber and wipe off the accumulated dust and dirt. Leaves a nice shine behind. I feel it's a little more effective on the dirt/grease than the normal 'detail spray' I use for the bodywork.
I have found that once an engine is clean (assuming no oil leaks) it is very easy to maintain it in the clean condition, basically forever. This applies to cars, motorcycles and scoots.