The best wy is to not get it in there to start with. i have been afflicted with poverty all my life, and seldom had any guns i was really woried about "ruining" so i have used valve grinding compuond, polishing compound, steel wool, and all kinds of other stuf that is supposed to "ruin" a good barrel. I have found that "pitting" has little effect, "dark" bores can be made to shoot well, and all sorts of things that are just not supposed to be. Most of these harsher methods actually improve the internal surface finish, and slow or eliminate leading, assuming you have a properly sized bullet, and aren't running astronomical pressures.
One 1958 vintage 4" 44 mag comes to mind. Had to get a new cylinder, and the barell was "salvaged " by lapping with valve grinding compound, followed by polishing compound. Newer(629-4) quit leading after i threw away an undersize mold, and very lightly lapped, then polished the inside of the barrel. BUT, I used to do tool and die work, so I have a "feel" for how much to lap something.
They are not much used anymore, but their is a lot to be said for a hollow base mold. I shoot a lot of them in my model 14 smith i use basically for bullseye and for rabbit hunting. It does very well with HBWCs, and as well if I use a regular WC that is sized right. I wqon't lead with a hollow base bullet, period. Any thing else, and it had better be sized right. Just my 2c worth