@terry9 The Fisherbrand™ Versa-Clean™, is a broad-base cleaner, with a combination of surfactants and corrosion inhibitors and some alkalinity, and the recommended concentration for use is not less than 60:1, but as much 10:1. The product details are pretty limited, and although it says concentrated, it is actually a diluted form of very concentrated surfactants. There is no way to know if a 2.5% solution will achieve the lowest surface tension. So, 2.5% (40:1) may not be enough, but its not cheap. And what is IIRC? When you say a hint of oil are you talking about oil as the original contaminant on the record.
The Tergitol 15-S-9 that I use for a cleaning solution is very similar to what the US Library of Congress uses to clean delicate shellac records, and is a non-ionic water soluble surfactant. It is a replacement for Triton X100 that you may often see discussed in these forums, and has the same performance, but at 1/3 the concentration and is not an evironmental hazard. Tregitol 15-S-9 is very concentrated and is quite cheap, a Qt is $38.70 and at about 4ml/gal
https://www.talasonline.com/Tergitol-15-S-3-and-15-S-9, would make about 250 gallons of cleaning solution.
A similar product to the Fisher Versa-Clean is Liquinox,
https://alconox.com/liquinox but it is likely more concentrated since it only requires 100:1, and at that concentration it will achieve a low surface tension of 29, but it is anionic and will foam.
R/Neil