For percussion revolver with 3F, I punched overpowder wads out of 1/8" thick felt, mixed up a combo of beeswax, neatsfoot oil (the substitute for lard or tallow) and parafine (our jelly jar sealant, not the Brit gasoline) in a double boiler which can be a coffee can or Mason jar in a pot of water), dipped the wads one at a time with big tweezers, and placed on wax paper. I have these in Ruger Old Army ".44 cal." (which is actually .457") and .36 cal (which is of course closer to .38" while modern .38 cal. is closer to .36" GO FIGURE??) They seal the powder against cross-firing between cylinders and both remove and soften fouling. They take up some useful space in a bp revolver cylinder but I don't think that's much of an issue in a shotshell even with relatively voluminous bp. Anyway, as Pete says, you need a lube of organic origin around bp; I'm not even sure the parafine qualifies as such unless you think all those palm trees, ferns, and ancient asparagus that were compressed and baked into crude oil allow that interpretation.
jack