I clean mine up with a file and then a reamer. I'd do it like Brian does, but the grinder is on the other end of the shop, and then I'd have to go around the tablesaw, and I'm too doggone lazy to walk 20 feet. Not too lazy to pick up the file and take longer to get the job done, though.

A wiser man than me might simply make his shafts over there next to the grinder, eh?