Hi,
one last word on vinyl's water absorption. If you look with a microscope at / into a groove it is revelatory --- nowhere near as smooth as say the end-wax, right?
Using water on it will soften the vinyl, even a 1/3 Isopropyl mix will, but less so. It will in the process lift vinyl particles almost similar to the small flakes on you skin (top dermis).
If you can feel over the groove area and it appears a bit rougher after cleaning, those are ever so slightly lifted vinyl flakes, they will bed down after playing, hopefully --- or get chipped out and leave more groove noise than before.
The other thing that makes me uncomfortable with steam cleaning is its very cleaning-action. I think that the cleaning is due to what's known as 'cavitation' in fluid technology, small bubbles of low pressure air, close to vacuum collapsing. On e.g. surfaces of metal, a ships or boat propeller, it will pit the metal after some time, and that so badly is must be replaced.
I ask myself what this can do to a micro-groove after extended, repeated cleaning.
Axel