In the GAF game when we are traveling 100 yards+, and ejecting brass all along the way, having shiny brass will make it easier for the brasser to find. A bag of 30-40 Krag brass which is very common at GAF matches, just sold on GB for $4.00 apiece! We'll have to start checking the brasser's pockets!
In my personal experience, nothing gets brass cleaner, including the primer pockets, then wet tumbling with SS pins. It is a little work.
B.N. Scotty