Mac, I have found that wonder wads over the powder help my accuracy, also I have had to go to the thicker patches once the barrel slicked up. Same as you I had to go from .010 to .018 pillow ticking. The Hoppes plus BP solvent is just great. The only thing I dont like about it is I leave my patches lubed for several months the solvent begins to attack the cloth, but it is a minor problem.
Using the Hoppes on the patch cleans the barrel on the way down, the overpowder wad lubed with borebutter keeps the patch from burning through on heavy hunting loads and just generaly helps with accuracy.
BP roundball shooting has brought a lot of fun back to my shooting, and the BIG bore bug is bitting hard!
That danged .72 cal double barreled rifle made by Pedersoli is calling! Along with that Howdah 20 ga double pistol they just came out with.
Have fun.