I use Lemon Grass Essential Oil.
I get it from http://www.bulkapothecary.com/
I give $13.59 for a 16 ounce container which I will say will last a long time.
I am using the pressed fiber pots for swarm traps.
I glue a piece of old comb inside and alittle dab of lemon grass oil.
I only hang mine about 6 or 7 feet off the ground.
I put out 18 traps in town and have caught 19 swarms so far.
I had a total of 39 traps out.
The tornado back in April got some but I have caught in every trap.
The traps I used the pheromone attractant in never caught anything.
I still have 8 traps to bring in full of bees.
Here is a picture of of a couple.