I clean my cases ultrasonically with the following process
Soak in water (no real length of time. Just long enough to get the insides wet)
Deprime wet
Use a cheap lee primer cleaner to get the major gunk out of the primer pocket (the lee cleaner uses a single cutter. Don't use a "brush" type unless you want a solid ball of rust when you're done)
Dump them right into a mixture of:
two cups of water
1/4 cup lemon juice
2 drops dish soap
Put the mixture with the brass into the Ultrasonic cleaner for 15 mins.
a 2 or 3 minute run through the ultrasonic with just water
Dry overnight
The above steps get great results as long as you don't put too many cases in the cleaner. By "too many" I mean about 20 cases of 308 or a box (50) of 9mm.
If you want to do more cases, add more time.
That being said, if you really want the "bright shiny brass" look then all the mxing, dumping, washing and waiting isn't worth it compared to just plopping them in the tumbler and watching some TV IMHO.
