I have one from Harbor Freight. Yeah, that Harbor Freight. So far it's worked quite well and will heat the solution to 145 degrees which is plenty hot IMO. My solution is something I picked up watching Youtube and distinctly cheap, one part white vinegar, 2 parts water, and one tablespoon dishwashing soap. After the cleaning cycles the cases get bathed in a solution with baking powder to neutralize the acid in the vinegar, then a soap and water wash, a complete rinse, then some drying time in a warm oven. Once that is all done the casings get polished in my vibrating tumbler for 2 hours. End result after about 3 hours is a batch of casings that look very good.
BTW, I decided to try the ultrasonic because I found that tumbling 308 rifle and deep revolver casings didn't do a lot to clean the inside of the casings, even after 10 or 12 hours in the tumbler. Using the ultrasonic solved that issue and the polishing doesn't take to long and does produce a nicely shined up casing.