I have set mine out in stacks for a few days--it turns into a bee,yellow jacket, hornet world war and the comb gets chewed up pretty bad. I tried stacking them upside down on top of the hives with the queen excluder in place--I was told that they would not use them to continue storing upsdie down as the combs slant downward. That did not work as well as I thought but maybe I did not give'm enough time.
Looking for your technique. Thanks!