Very clever idea -- plus you get the Box Top from buying the Avery labels. In defense of the prior coordinator for not marking the bags, BTFE doesn't require it.
I have found the EASIEST way to mark box top baggies 4 submission is to make address (avery) labels and run them off, i could not believe our former coord. did not think or even realize each baggy needed to be marked. You would not want the orders to get mixed up or marked 4 wrong school!