Are you sure it's lead accumulating on the forcing cone?

On my revolvers that area gets mostly only powder and primer residue, and it goes off with a little solvent (I use M-Pro 7 cleaner) and a simple toothbrush. Not much effort involved.

PS: BTW, If you don't know it already, a neat trick to take the burn rings from the front of the cylinder on a SS revolver, is using metal polish (Brasso, Mother's Mag Polish, whatever). Just polish with a rag and it looks like new immediately. Gun solvents do little for those nasty burn rings.