When I'm inspecting the frames of a colony that appears to have died from starvation, I just hold the frame horizontally and give a couple raps from below with my hive tool on the end bar/top bar joint. Most of the bees fall off, including the ones in the cells. I don't go crazy beating on the things, but a couple quick raps gets 95% of them off. The rest I leave for the bees to finish.