I use a Harbor Freight Chicago Electric Professional 2.4 pint ultrasonic cleaner with great results. Just looked and they do not offer that model now as I have had it 10 plus years.
First, I NEVER put the cleaning solution in the machine "tank" itself, too messy to clean up. I have some 600ml Pyrex beakers that cleaning solution is placed in, along with the cases to be cleaned. Put this beaker in the cleaning unit "tank" and fill cleaning unit with water surrounding the beaker to the proper maximum indicated level for YOUR cleaner (ultrasonic waves will transmit into beaker and clean the cases just fine). I use a piece of cardboard and cut a hole in it to snugly fit the beaker and place this contraption on top of the cleaner unit with the beaker in the "tank" water. The purpose of the cardboard is prevent the beaker from migrating around in the cleaner "tank" when it is in use.
FWIW-This is my process for cleaning 300 Win Mag cases used for work at 1000 yards:
1. Clean primer pockets FIRST. They will be like you want them after ultrasonic cleaning is complete. Not so much if you don't clean them first.
2. Have used both Iosso Case Cleaner and CLR (not mixed). Prefer CLR as it is cheaper, easier to clean out of the cases and does a great job. My friend says white vinegar works but have not tried it yet.
3. Put the cases in the beaker in an upright position standing on the case head so they completely fill with cleaning solution and do not have air pocket voids. (I prefer 5 cases at a time).
4. Set my Harbor Frieght cleaning timer to 480 seconds (max time), then start cleaning cycle. It makes a pretty annoying noise I might add!!! Your wife / by-standers will love it...
5. After cycle is complete, remove and rinse the cases out with hot water until you reach a complete rinsing of the cases you are comfortable with. Set cases aside.
6. Place 5 more cases in solution and repeat this above madness.
7. While the next batch of cases are cleaning, use compressed air to dry the cases. (this is why I only do 5 at a time).
8. After all cases are cleaned and air dried, I like to put the cases in a MTM case box and leave them air dry for a day or three to ensure no water remains.
Iosso gets the cases a brighter, shiny finish but is a pain to rinse. Not quite as shiny with CLR but much easier to rinse. Targets can't tell the difference in gleaming and shiny cases vs. just good and clean ones. Plus, if you shoot a bad group, you can blame it on this instead of your ability to shoot well.... LOL
YMMV
Some of this process I obtained from Jason Baney. I seem to remember he posted his cleaning process on this forum, or, it may have been the 6mm forum. If that is not the case, then I got it from our telephone conversations many moons ago...
Shoot small folks!