Hey Sir Lil John: now that is a good idea, I mean make the swarm come to you,,,,, using a brood frame as an attraction. Never heard that one, makes perfect sense.
I realize nurse bees have a very strong attraction to brood and I use that brood attraction to prevent absconding when introducing bees to a new home. My experience is the nurse bees will tend to the brood and if necessary will give there life for the babies. I have never seen nurse bees abandon brood, although I am sure this event has happened.
Blessings