For muzzle loaders, I have only used wads in cap'n ball revolvers. The wads are either a waxed card (card stock or milk carton with a smear of lube over the ball) or a felt wad soaked in lube such as an ox yoke wad or wonder wad with no lube over the ball.
In a patched ball rifle I see no need for a wad unless there is just not enough lube in the patch to keep fouling soft.
I do use cards and wads in my paper patch bullet rifle too but that is a different question altogether.