Its been a while since i have been on the site, but IMO, ultrasonic cleaning is very effective and if you don't mind building, they are actually easy to build. As for as solution, distilled water is the primary component as it should be ultrapure. no compromise on it. Second, i like a little 100% isopropyl alcohol if you can get it. No residue from it. 90, 70 or less will have water and may have other components (ie fragrance, etc). you only need a little 1-2%. IMO, the cavitation occurs more readily with a little Isopropyl. A good surfactant/detergent also is recommended if you have real dirty records. I like Triton 100 but tergitol , Kodak photoflow, or even a little dawn dishwashing detergent will work. you do not need much. one or two drops of triton goes a long way. I also like to rinse afterwards just to make sure there is no residues. I will air dry after rinsing with distilled water. Finally, the solution should be warm, about 100-125F that goes into the ultrasonic bath. That helps improve the action of the surfactant. I built a unit for less than 200 dollars about 8 years ago
