A friend out west sent me about 600 pieces of that free,it has quiet a bit of tarnish on it almost to the point I about threw it in the recycle bucket. But what the heck I had the time so I soaked it in Lemi Shine for a couple hours stirred or shaken in the container occasionally,does a nice job cleaning out the inside of the case as well.
Follow that with a good rinse with warm water and spread out on a towel in the hot sun to dry for a couple hours. The Lemi Shine turns the black tarnish a very light pink color and a few hours in the tumbles with your favorite cob & polish make it look like brand new.
Mine was all 9mm NATO so it had crimped in primers,they punch out easy compared to some of there rifle brass counterparts. I use a Hornady primer pocket reamer tool chucked in a cordless drill and knocked all those crimps out in just a little over and hour.