That is interesting that it worked well. Because that seems to lead credence to the ideas of using the surfactant to get the cleaning power deeper into the grooves.
Did you notice the tell tale signs on records as you did the second or third cleaning step with reapplying the surfactant and running it though another cycle?
The process does seem time consuming. But is the unit quiet enough that it can be in the same room while you work on cleaning? With my current ultrasonic tank I have it in the garage cause its too loud to listen to.