We always used paraffin wax on the crimped end for our waterfowl loads. Simply melt it in a small container and apply it with a small hobby paint brush. Actually it was the same wax we used to remove down and pin feathers from the birds after the hunt, just applied with a larger brush. I am not sure I would use wax on the primer for fear the heated wax would eventually cause issues with the firing pin. Perhaps the nail polish is a better choice on the primer. I might also worry about the nail polish on the crimped end because when heated upon firing it may redeposit on internal barrel surfaces. So for me, wax on the crimped end, nail polish on the primer and then placing them in a plastic bag should give you shells that will last a life time.
