Fear not, the HG produces cavitation - Interesting All-in-One Ultrasonic Cleaner - HumminGuru | Page 38 | Steve Hoffman Music Forums - see Post #930.
The HG only has 350-ml of fluid, so it does not need a lot of power and the lower kHz, the lower the power required for cavitation. With the HG, the two 40kHz transducers (~30W ea) are located one each side, very close to the record; located exactly where the big hole is in the aluminum foil.