Assuming that all the debris is simply under the cowling but not INSIDE the engine itself….I would use a high-pressure nozzle on a water hose and spray it down good from a distance away. I have a brass nozzle that will reach clear up under the eaves of my house; that’s what I would do.
You should find that the water spray will dis-lodge most of the problems and blast it away from you.
It isn’t going to hurt the motor to get it wet for a few minutes; just refrain from blasting into the carburetor.
Then; I take some dishsoap and toothbrush and finish cleaning that way. Gets most of everything and keeps the dust down.
