I have never had a problem with "The Dreaded Carbon Ring" in my 357 revolvers after shooting 38 Specials, actually not carbon until after several hundred rounds fired w/o cleaning (mostly powder, lube, debris fouling). I have gotten used to using a bore snake on my revolvers, maybe after a solvent soaked mop/patch is run through, and one or two trips through the cylinder produces shiny chambers. For solvent I mostly use Ed's Red or my version of it. Stubborn barrel leading is removed with a soak with Kroil then a bronze brush (sparingly) to scrub the barrel (but my cast bullets rarely lead my barrels). For really bad leading, which I have not experience since I figgered how to size my cast bullets, I have a Lewis Lead Remover....