With the tool I'm considering buying, do you know if the die is rotating with the screw/wheel when rotated, as I've tried to illustrate in image B, or if it stands still as I've tried to illustrate in image A?
I used to import them from India for years and know their tools very well. There were tools that I didn't touch and tools that were ok and usable. I could examine them at the exporter's site, the customer here has to try and error.
There is no definitive answer as some dials are easier to clean than others. What ever you try always try in a small area preferably an edge which is hidden when assembled into the watch case. One agent that sometimes works is human spit try some on a cotton bud and test.