Re: Cleaning brass
Personally, I think that brass cleaning begins at the time it's being fired.
My serious LR rifle has its ejector disabled, and my cartridges get individually hand-chambered. So the case pretty much goes from box to chamber to box, no detours in between. This goes a long way toward excluding grit, etc. from the equation.
I tumble my brass before resizing/decapping, mostly because tumbling deprimed brass tends to end up with media crumbs in the flash hole; while decapping previously tumbled brass tends to eliminate such issues.
I lube with RCBS Water Soluble Lube, wiped on with finger tips ala Imperial, etc., and finish my completed rounds with a wipe using an soft cotton cloth moistened with rubbing alky. The Lube somewhat resembles a thicker-than-usual dish detergent and probably contributes to case cleansing.
If some neck soot still remains, I'll spin the loaded neck with some 0000 steel wool, and re-wipe the cartridge with the alky cloth.
How you handle your brass on the line makes a significant contribution to this discussion.
Greg