^ ^ ^ Excellent information. I've been using a small Hornady ultrasonic cleaner for a couple years now for small firearms parts. It does come in larger sizes. Mine has worked fine with no problems. It has only one power setting, but does have a digital timer that can select several different cycle lengths. I usually do have to run it through several cycles to clean dirty stuff.
I have been spending money for dedicated cleaning solution, one for brass, the other for steel. I think I'll try using regular dishwashing detergent. All it takes is a few drops of any of this. Unless you do a lot of parts, the solution, whatever you use, will last a long time. Because the solution gets contaminated with dirt, grease and other grime, I change out the solution on my little tank with every new batch of parts, so my volume is, obviously, low.
While I use mine mostly for cleaning of primer pockets and the inside of rifle and pistol cartridge cases, it works well on all steel, aluminum and brass small parts. I understand it is not recommended for nickel plating, but I do not know if this is true. Have not experimented with that.
It does NOT polish, very well, though. If you want the surface polished, throwing the cases or parts in a vibration or roller tumbler with either old fashioned ground corncob, walnut, or the newer stainless pins will get them nice and shiny.