I use a patch soaked in Kroil before leaving the range. Let the Kroil soak for a few hours and wipe dry with a patch.
Then patches with alternating solvents, until they all come out clean (some remove copper better, and some remove powder residue better).
The Kroil loosens up the fouling, a trick I learned from some bench rest loonies.
I don't use brushes much anymore, other than in my ARs.