The best treatment I've found for removing old mold release chemistries (if that's what it is) is not steaming but enzyme-based record cleaning fluids. Buggtussel Vinyl-Zyme is pretty good. AIVS Enzymatic is better. Others like Walker Prelude, which I haven't tried.
With any enzyme fluid you need to let it sit on the record for several minutes, making sure to use enough solution so it doesn't dry out. Brush the fluid around every minute or two to keep the grooves coated with fresh fluid and let the enzymes do their work.
After that you need to remove the fluid, ideally by vacuuming or (distinctly second best) with clean, lint free cloths. Then follow with several rinses with VERY pure water. "Very pure water" means the water provided by AIVS, MoFi, Walker or something similar, not distilled bought from Walmart.
This takes longer than steaming, but it works better IME.
With any enzyme fluid you need to let it sit on the record for several minutes, making sure to use enough solution so it doesn't dry out. Brush the fluid around every minute or two to keep the grooves coated with fresh fluid and let the enzymes do their work.
After that you need to remove the fluid, ideally by vacuuming or (distinctly second best) with clean, lint free cloths. Then follow with several rinses with VERY pure water. "Very pure water" means the water provided by AIVS, MoFi, Walker or something similar, not distilled bought from Walmart.
This takes longer than steaming, but it works better IME.