Aren't they usually vibrating rather than rolling?
Two types are used in industry, vibratory and tumblers.
That sounds like a bit of a cock up...I made a crude, rude and effective vibrating one.
Thick wall plastic bucket, old jam container from a bakery. (Free)
Powder pumice Local metal shop. (3 packs of biscuit)
Mix the powder with water until I got a paste, thing single cream.
Then to make it vibrate, I On line purchased 4 lady personal massager's(Rude bit)
Fitted them into thick wall plastic pipe. (work cast off, Dry riser systems)
Added the brass items, the tubes and switched on.
Left.
The brass came up clean, but dull. But a few minuets with brasso they looked good.
I remember being shown a de-burring technique at a local arms factory - they were doing the tubes for mortars, basically a lump of steel tube about an inch and a quarter diameter that has a bunch of holes drilled through it crosswise. The tubes were loaded into a cage type tray and then shoved into a sealed chamber which had gas added (methane I seem to remember the guy saying) when it got to the right explosive mix a spark plug ignited it and WOOOOMPH. The parts came out sort of bronze coloured and sans burrs. Sort of like flame polishing plastic. No doubt there was a reason for doing it that way but it was probably close to 30 years ago so I didn't think to ask.
The chamber was very beefy as I recall with a door resembling something you'd see in a bank vault in a Hollywood film. Not something I'd recommend trying at home though.Sounds like a good method for Darwin award participants to try out