When is your swarm season? Normally you use the Demaree system just prior to that, before any swarm cells are started. There are variations on how to Demaree the hive, are you putting the queen in a bottom box with a frame of eggs and the rest drawn empty comb, adding an excluder on that, then putting honey supers on top of the excluder, then the rest of the brood above that? I would wait for the night time lows to come up a bit more, which would be closer to swarm season I am thinking in your area.