Sparkie- I find cardboard too flimsy and wooden boxes too heavy, so I made a few swarm boxes out of 3/4" pine framing and covered with 1/8" luan that I pulled out of my scrap lumber pile.
I use these as swarm traps as well. I use commercial pheromone and it works really well for me.
This year was crazy for swarms around here (Florida). I turned down 30 calls because I was too busy to go collect them. I took all the calls that were near home and easy to get to. Two of the swarms absconded, but I still wound up with 14 new hives and/or nucs which I sold. I wasn't working my bees much this season due to family obligations, and I had a couple of pallets of old hive bodies sitting around. I took 4 swarms out of the stacks of boxes- I've never had that happen before!