Built one of those 'Heath Kit' ones about 25-30 years ago.. I used to use it for cleaning diving regulator parts during the rebuilds. Used vinegar (regular 5%) it did a great job of removing corrosion pretty quick, but over time, the vinegar, under the ultrasonic action, would eat tiny holes in the bottom of the stainless steel tub.. The machine would run for maybe 5 minutes every couple of hours, and lasted about two years.. I wore one out, and still have the second one I built, but only use it maybe once a year to clean a part that nothing else will touch.. The should work well with one of those new Oxi cleaning agent you couldn't get back then.. That would solve the problem of acetic acid pin holes in the tub developing