Nothing is ever certain in muzzle loading, but in my experance the wad will improve accuracy about 70% of the time in most guns.
I have to put a dry wad on the powder add enough corn meal the way I originally deceided how much was by putting a wad at the lower end of the QLA and filling it level to the top of the muzzle then put a greased wad on top of that, it works. But since I will be shooting the new Hornady bullet for a conical I can get minute of angle by dumping 100gr in and shoving the bullet down.