I wouldn't suggest trying this with a swam but all of this discussion leads me to recall of how I once dealt with a large wasp nest under my dad's eave maybe 25 years ago. I don't remember if we even had wasp sprays around back then but I had a clever idea and got a can of ether (diesel engine starter fluid in an aerosol can). I then got a long lighter and held it out maybe 12" in front of the can of ether and sprayed it towards the nest for just a second. A large wide flame briefly engulfed the nest. The eave showed now damage at all and all of the wasps were crawling around on the ground without wings. Not a single one had managed to fly away. Understandably, my dad just shook his head but I reminded him that my fascination with fires was something I learned from him.
