It's basically a sand blast cabinet, but I mostly use glass on a low pressure. Quite time consuming, but I'm doing it to please myself, not a money making venture.
Back when Gandma was a boy and I worked in the cloudy valleys of The Chilterns, the place I worked had a massive vapour blasting cabinet. It certainly wasn't unusual to see a big box of engine bits etc hidden under the bench for a bit of 'pocket money' when the boss went home
The stuff that came out was quite frankly excellent.