If the taper's not damaged, you shouldn't need anything more than to make sure the taper's clean and dry before assembly. The joint drives through friction between the axle and hub, not the key, which is there purely as a locator. Tighten to the specified torque and drive for a day or two, then re-torque because the joint may have settled a bit. Once the torque remains constant, you're done.
2015 BMW R9T, 2010 Ducati 1098 Streetfighter S
2009 Kaw 650 Versys, 1967 Triumph 650 TT Special