If it's a clean polish you want without the need for elbow grease, a metal vibratory bowl (or tumbler) should be on your radar. Not to be confused with a vibratory feeder, which Google will spout ...

To make a basic rock tumbler, all you really need to do is ... a similar electromagnet arrangement to what he used in the vibratory bowl feeder he built last year. Pulsing the electromagnet ...

Ceramic tumbler media makes the entire rock tumbling process more effective, improving delivery of rock tumbling grit, These rock tumbler ceramic pellets are safe to use with any rock tumbler.

Such contraptions are known as, unsurprisingly, rotary rock tumblers. But what [Fraens] has put together here is a vibratory tumbler, which…well, it vibrates. If this was Rockaday we might go ...