if you are going to use an excluder, you have to let them start working the super first. if you put the super on with just foundation, or strips and then an excluder, they probably will not store in there. if they run out of room below from storing in the brood boxes, they will swarm on you.
if it's a metal excluder, pop it in the freezer. tomorrow give it a twist or a whack and most of the propolis will break off.