Ultrasonic Cleaner

I was reading a thread a little while ago and someone mentioned how inexpensive ultrasonic cleaners have become.  So a quick search on eBay turned up a couple of choices.  For the type of cleaning of small parts I do, there is a 35 watt model and a larger 60 watt model.  I opted for the 60 watt model which was only $65 including shipping.

The suggestion for cleaning solution is either plain water or water with some liquid dish soap added.  Both worked well on a dirty part, but didn't do much for a greasy part.  You can just see the dirt 'boil' away from the threads on the studs.

For greasy parts, I decided to try using some parts solvent (basically kerosene).  Fairly safe from a flammability stand point, so I wasn't worried about any vapor being ignited by the electrical components of the machine.  These pictures are the end cap for the generator, before and after cleaning.