Cleaning the brass is a rather simple procedure. It requires a brass cleaner(either a vibrating or rotary cleaner), media and, of course the spent brass.
I'm using a Hornady vibratory brass cleaner with Lyman Turbo Tumbler media. I put about 3.5 lbs of media in with 100 casings of .270 WIN brass and turn it on for 4-6 hours. One note of safety is that I tend not to leave it running while I'm out of the house...better safe than sorry.
I've heard that that you can leave the brass in the cleaner longer if
Hopefully when you're done the brass should come out clean and ready to go.
-Steven Kipp