Thanks for the tips guys. Scrubbing a polished aluminum part with a toothbrush is out of the question because it will leave fine scratch marks. I'm liking the idea of hot water and liquid dish soap. A large ultrasonic cleaner would be deluxe. In the meantime, I am thinking I could get a pot of water on a low boil, add a small amount of dishwashing liquid soap, and agitate the water with a hand held mixer like the kind used to make cake batter. What do you think about that?

For small parts, I can probably fit them in my small Harbor Freight US cleaner.

John, thanks for the kind words.