Anything reflective is right out, but I have some tiles of various plumage laying around and I'll run a materials test on them. I'll post an update (this will take a few days to set up).

My first response is: wrong process, I'd use a water cutter with an abrasive added to the water for this particular application. But my second response is: you can't be sure without trying, but I predict it will either not work at all or it will take an insane number of passes.

maybe cnc sandblasting with emery will work for that, but it will produce a lot of airborne crystalline silicon dust, which causes silicosis if animals breathe it. maybe better to cut your clay to rough shape before firing and then wet grind to final dimensions after firing if necessary. hot isostatic pressing may also be an option depending on the use