Clean the brass before resizing as it will save your sizing die. Carbon deposits and grit are hart on dies. If you are just decapping with no sizing, cleaning is not as important but it takes too long to make decapping a separate operation. Just isn't worth it for pistol.
Most people have a vibratory tumbler and really any will do. I will tell you that a rotary tumbler, using ceramic media and a liquid cleaning solution consisting of water, dish soap, and lemon juice is the best way to clean brass. Looks better than new and you don't have to concern yourself with any airborne particles of lead etc as a result.