[mrerick]

Count on at least a couple of mechanisms when you try various chemicals, additives and abrasives. Chemical conversion and actual abrasion. Polishing stones useful for flat surfaces.

Both can be aggressive or mild, fast or slow, but in any case I expect quality is time consuming.

It's likely that overall processes can accomplish better control through chemical conversion techniques.

Bead blasting techniques will leave a matted surface. Sanding will leave abrasion marks.

The bead blasting techniques will be reasonably random and uniform. Polishing out a surface prepared this way may, in the end, be easier because there will be fewer identifiable marks. But... the entire surface will need to be uniformly polished. That is also difficult and time consuming.