Humminuguru owner here. Because I was curious, I bought one of those 6L ultrasonic baths (
this one) from eBay and tested.
I use the method that Tergikleen outlines with their product:
- Use Spin Clean to give a surface cleaning/prewash.
- Fill up the ultrasonic cleaner with Tergikleen / reverse osmosis water at 10 drops/gallon dilution.
- De-gas the solution (i.e., run the bath for 10-30 minutes).
- Run up to 6 records through the bath at 38 degrees Celsius for 30 minutes.
- Rinse off with reverse osmosis filtered water using a plastic garden sprayer.
- Wipe down labels and let air dry.
I found that this method gets my records EXTREMELY clean. They look and feel cleaner than my Humminguru method of using G2 and pressing start. Is it noticeable enough to switch me over to this new method? Probably not. The Humminguru is a hundred times more convenient and serviceable with new vinyl. I will probably use the ultrasonic cleaning method with used or old vinyl.