Hey Handloader,
After many years of polishing cases by hand and then later moving up to the much better method of turning them on a hand drill by sticking the case mouth on a mandrel chucked in the drill, I finally broke down and bought a big Lyman vibratory case cleaner that I have now been using for maybe 20 years. In that time, there were several times I forgot and left the thing running for 24 hours or more. It is still working just as it did when I bought it.
I paid a good bit for that Lyman cleaner back then, and I would guess they are a lot more expensive now. However, I have seen vibratory cleaners for sale at Harbor Freight stores at a very low price. I doubt if the Harbor Freight unit is as well made as my old Lyman, but for the price difference, I think I would at least try one of the Harbor Freight ones these days.
Best wishes,
Dave Wile