Your wife or you has the same taste in Granite my wife has.....lol She went with a composite granite sink too. We have so much lime in the well water, stainless lasts about 3 months.
Vibrating for dry media (only), rotating for wet media like STM or in my case stainless ball bearings.
You can get a double drum rotary rock polisher (same thing as the Thumlers) but smaller and 2 drums instead of one at Harbor Freight everyday for less than 40 bucks.
An RCBS Sidewinder is also a very viable alternative, if, you can find one.
Thumlers found a new market IMO. They were in the lapidary (rock polishing) accessory business for years.
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, it's about we