A thought I have had that I don't think I've ever seen mentioned is this:
When swabbing between shots (regardless of what liquid is used on the patch), how much of the fouling is pushed down the bore ahead of the patch? With propellants that are very "dirty" (black powder, pyrodex), I see a lot on the patch when it comes out, but I always wonder about the amount that was "piled up" on or near the flash hole before the new charge is placed.
And . . . so as not to hijack this thread - how does Iso/WW compare to others in "trapping" the fouling on the patch?

IM jaybe