^^^^^It sort of looks like a primer pocket sort of tool, except that it isn't.
Looks like someone solved the problem of the bristles fraying and bending. Looks like a cast part, which likely isn't a home-gamer's one off, but it's odd that none of us so far have ever seen one before.
Yes there are, and everybody was correct except me! The guy who has it didn't think it would work well for cleaning primer pockets, so we both overlooked the obvious .Yep, several on eBay right now. They were made to be run with a 1/4 drill motor. Put your fingers on the wings, or in a vise, and push in with the case.