Everybody has their favorite formula. At work, all the watches and jewelry are cleaned with powdered Tide and a generous splash of ammonia. Whether in the ultrasonic or by hand, this is what we use. We never put a cased movement in the ultrasonic.
Some of the jubilee bracelets are so filthy that we must give them several cycles in the ultrasonic. We also use a commercial steamer to blow out the dirt that hides where you can't reach with a brush and won't rinse away.