Primer pocket cleaner
RCBS makes those little wire brushes that thread into the same handle as the case mouth brush. After tumbling and then sizing and depriming cases, that little brush gets twirled in the primer pocket. A very minute amount of crap comes out, but I can do about 10 cases per minute, and don't get all anal about how clean the pockets are.
I know some hand loaders that have done thousands of rounds that never ever clean primer pockets or worry about flash holes. And there is this other guy that reams the flash hole on all his brass. Whatever. Personal preference.