On a similar vein I use a can of febreze air freshener, horrible over-scented stuff, to spray around when I have collected a swarm. Once the bees are in the skep/box I spray the site where the cluster was with it and it confuses the hell out of the stragglers and stops them returning to that site.
My only advice would be don't leave it in the car, my then 7 year old emptied about half of it to "make the car smell nice".
febreze is indeed orrible stuff, my middle boy is alergic to even a whiff of it and comes up in a rash