I prefer Japanese sharpening stones or those DMT diamond whetstones. It’s relative easy to 3d print a jig that converts a woodworking honing guide into an IC holder and you get a feel for how many passes to do very quickly before slowing down and checking each pass.

I like it. I've used sandpaper to solve some interesting problems in the past as well with great success. I suspect we are only seeing the beginnings here in a trend of high-tech applications of fine grit paper.

I've heard that boiling epoxy in molten colophony for a few hours, like a long-cooked version of rosin potatoes, will also dissolve it. I haven't tried it myself. Colophony is much more expensive than sulfuric or nitric acid, but safer to handle (when not molten) and often easier to get.

I appreciate the effort, but the bar is already very high when you recommend a SEM in the same breath.

There was a sandpaper expert in that company associated with sour-tasting fruit which shall not be named. I believe you guys have met, though I think by that time he already pivoted to making the perfect cheesecake.