The old ring-waxed fiber wads (Alcan, Remchester) were pretty skimpy with the wax, and cost was likely one factor. Too, the wax was hard.
Blackpowder shooters commonly use a mixture of Crisco and olive oil, or a variation thereof, and just lightly dip the whole thing. Compression upon firing should squeeze out any excess, which I think would be a good thing. If you use a plastic base wad or don't leave them on the shelf a long time, bleeding into the powder should not be a problem.
As noted above, a double boiler is a must.
