Machine shops use it to clean all kinds of metal parts. It's just media blasting in a blast cabinet and the media of choice is glass beads. It works extremely well on aluminum that has something less than a full polish on it. It leaves more of a satin finish. The downside is that when it's used on engine parts, particularly internal parts it takes a while to get it cleaned out of blocks and heads. It leaves a fine dust that can cause engine damage if not removed. I've done this dozens of times for intake manifolds, aluminum heads, alternators that I've finish polished etc. It's very effective at making an old part look new again. Of course you can then polish it as needed to get the finish you desire. It's not expensive and doesn't take long to do. You can buy a satin clear coat paint from manufacturers like Krylon that will leave the satin finish I think you are looking for and it won't oxidize. I've also used this process on a fairly hard to find set of original Shelby valve covers (60's vintage) that had a black krinkle finish with bare aluminum colored fins, they turned out like new. You can buy several colors of krinkle paint also.
