Bushmaster:
That depends on how you want the pad to act. If you want a "smooth, non-stick" nature, coat it with stock finish until it's slick. If you want it to hold on your shoulder, do nothing. If you want a temporary slick finish, use Armour All as mentioned above. BUT... once you use Armour All it will soak in, and any stock finish will be very difficult to dry atop that stuff.
In any case I'd work the pad edges down to at least 400 grit before anything goes on. If you haven't already.
Best, Kensal