Now John, the challenge becomes how do you mass-produce this
Don't have too, in the US they already are, Gemstone Equip, Simi
Valley CA & several others already do. You can buy less
expensive ones from firms that sell reloading equipment &
supplies to shooters. They use vibratory tumblers to polish the
brass cartridges before reloading.
While assorted sizes of ball bearings will work as the
burnishing agent, the addition of other shapes, flying saucers,
18 ga pins 4-5 mm long, etc will get into crevices & other small
areas of items to be polished.
In the US steel & stainless steel shot of different shapes is
available by shape & in assorted shape packages. The stainless,
while higher priced doesn't require the care (rust prevention)
carbon steel does. Tupperware (plastic) containers make good
vibratory tumbler containers.
Any small motor (preferably one with ball bearings) can provide
the jiggle. If needed, attach a small segment of a broken pulley
to the shaft, to cause an out of balance condition. This is what
makes the thing jiggle. Tighten everything securely, the jiggle
has a tendency to work things loose.
Vibratory tumblers are more efficient than rotary tumblers
because the item is being burnished by the media all the time the
unit is running, not just while its sliding down the top face of
the charge, as in a rotary tumbler.