I wonder exactly they used in olden days or at least what was common.
This is from a 1864 Starr fire arms catalog on loading procedures.
"The ball must always be lubricated, to prevent the barrel from leading. The best method is to fill up the chambers (after the ball is rammed home) with paraffin, spermacetti, or tallow, so as to completely cover the balls. This performs effectually the lubrication and protects the charge from dampness."