The main function of the lube is to keep the fouling soft. Trex or tallow work well, add beeswax if you need a stiffer mixture. If you are using enough lube the muzzle will be wet with lube after taking a shot. If the bullet grooves don't hold enough lube you can put some under the bullet with a tight card or beeswax wad over the powder. You should be able to shoot all day without cleaning the bore as the bullet will clean out the fouling from the previous shot.
Daz