Cola308
I use 0000 steel wool also , only on the outside neck & shoulder area after I fire each round , works good in two ways , 1 I can check condition of the case for defects & 2 I can pace my shots . As far as cleaning I cleaned my brass with corn & walnuts , once I cleaned in a wet tumbler with stainless steel pins I will never go back to dry . I also cleaned my pockets with the uniformer , now I pop out the primers with a universal decapper without sizing the brass. The brass comes out bright an clean inside & out ,even the primer pockets.
Never liked the idea of the carbon buildup inside the cases , even the media would sometimes build up in the shoulder area , I would see some media on the press when sizing. If your looking for brass looking brand new every time , get a wet tumbler . I changed after 25+ years of cleaning with dry media , gave the vibrater an pounds of media to a friend.
Can't say your groups will get any tighter but I feel it better all around for your dies , reloading & your chamber , its like shooting store bought ammo , only it shoots better.
Hope I Helped . Chris