I thought I had all the stuff I needed to deal with valves. I was wrong.
My first valve has been sticking lately. I went through multiple rounds of cleaning the piston and swabbing the casing using the degreaser. Then I polished the piston (which looked nice and clean/shiny, but...). Nope.
I have been dubbing R-R tapes lately in my practice area, and cleaning the heads between each pass. So I got the alcohol I was using (99% isopropyl) and cleaned the piston with that, then swabbed the casing with a cloth that I had poured some onto. That did it!
As good as the degreaser is most times, there was something stuck there that was stubborn. AND, I have used this stuff as spot remover on the carpeting - works great!
Here is the stuff:
https://smile.amazon.com/gp/product/B09C4XKXYH/