I'm sure most of us are talking about traditional sidelocks, and most of us are shooting a PRB. You seem to be talking about inlines, and modern bullets. The OP has a sidelock, and is shooting a PRB.
If I do shoot an all lead conical in a sidelock i'll use a bronze brush, and maybe some Hoppe's 9 to loosen up the lead first. Then i'll flush, because it's the best way to clean out the breech channel. This won't be often, because i'll use a PRB 99.9% of the time.