I think that acetone 'eats' plastic. I would never use it on Amiga.
dishwasher is not so dangerous as it seems. it would give the best cleaning, and many people have used it. some even say that similar process is used in making motherboards.
I used dishwasher on some PC keyboards and RAM modules with no problems (even using the soap which is not recommended), just need to let it dry for at least a week.
distilled water might not be a good idea, I heard its corrosive.
