I wouldn’t advise using any spray instecticide, partly for the flammability concern, but also since a a lot of the vapours are going to come right back out of the exhaust of the vacuum cleaner. Back in the day, I once helped a friend destroy a wasp colony that had built a nest in the wooden frame of his parents house by wedging the nozzle of a vacuum cleaner adjacent to the entrance and leaving it running for about 30 minutes. It wasn’t particularily energy efficient, but it was fun to watch in a cruel boys fashion. Once we stopped the machine, we tried listening through the nozzle, the wasps were still very much alive and sounded extremely pissed. I smoked a pipe back then, so we tried firing the pipe up, then I held the stem in the nozzle and my friend turned the vacuum on again for a few seconds. The combination of the nicotine and the particulates in the smoke killed the wasps in a minute or so. We dumped the bag out after to check, and there were about 100 bodies.
If you don’t smoke, try to suck up some fine dust - wasps breathe through tiny pores in their skin, clogging the pores will suffocate them, no chenicals needed.