I used my ultrasonic record cleaner for over 30 years with excellent results and never had the need for any additional cleaning methods. Most of my records were purchased new and I only purchased used records that were visibly in excellent condition with no visible defects or contamination. So for records that are visibly dirty, perhaps a precleaning step would be beneficial.
When I assembled my first ultrasonic cleaner I used several surface analytical techniques in my laboratory to evaluate the effectiveness of my ultrasonic cleaner. My initial experiments to evaluate several ultrasonic bath variables were done on a sacrificial record that was cut into ~1 cm squares. Controlled amounts of various known contaminants (oils, greases, lubricants, fingerprints and hard water) were applied to these samples. These samples were then heated in an oven to drive off any volatile species and to induce interdiffusion and/or any chemical interaction, which would simulate aging and make them more difficult to remove. These samples were then analyzed before and after various ultrasonic cleaning variables, one of which was exposure time in the bath. The results for exposure time indicate ≥ 95% removal of all contaminants after 1 min exposure and ≥ 97% removal of all contaminants after 2 min exposure and ≥ 98% removal of all contaminants after 3 min exposure. There was some variation in the rate of removal depending on the particular contaminant.
These 1 cm square samples were suspended vertically in the ultrasonic bath and were static and not rotating on a spindle as in a typical record cleaner. To compare these static exposure times to a rotating spindle, the time has to be multiplied by 3 because 1/3 of the record is in the bath solution at any given time.
We also used the same analytical techniques to compare manual cleaning with a brush using a surfactant in distilled water solution to several RCMs using their recommended cleaning solutions. We found that they all removed a significant amount of contaminants. The differences in contaminant removal were more similar than different. For these cleaning methods, the contaminant removal varied between 60 to 80%. Mineral deposits from hard water and fingerprint residue were typically more difficult to remove with these cleaning methods. None of these cleaning methods came close in contaminant removal to the ultrasonic cleaner which had a contaminant removal of ≥ 98% in these experiments.
Besides its superb cleaning capability, the speed of cleaning with an ultrasonic bath is hard to beat. I could clean, rinse and spin dry 10 records on my spindle assembly in less than 20 min. The total time includes mounting the records and removing the records from the spindle.