I personally haven't tried them and probably never will as I have and use red loading tubes from Dixon's Muzzle loading in Kempton PA. When you use pellets, you have no way of adjusting the charge accurately to suit each individual gun, and they're probably more money than pouring regular Goex into the tubes prior to going to the range.
As far as fouling goes, try using Butch's Black Powder Bore Shine, distributed by Lyman. Pour just a little bit on a couple of cleaning patches then wipe the front of the cylinder as you rotate it when the revolver is at half-cock (No loads in the cylinder!). This will clean the cylinder face and the front of the forcing cone as well. Then use a piece of paper towel to wipe off the excess until it dries from the drying agent that is in the solution itself. Then cap-off at the firing line to make sure that the nipples are clear of any foreign matter, then load & shoot as normal...Works great!! This stuff emulsifies BP on contact, without any scrubing needed.
My son's Remmy works good with 25 grains of 3Fg Goex and a wonder-wad and a .454 ball. Be consistant in how you seat the ball on the charge for maximum accuracy and have FUN! :wink:
All the best,
Dave