Serious question----can you buy wasp killer (spray cans) in your neck of the woods? I've tried for 2 months to find some here but apparently Mn. is out of it. Meanwhile I've got 2 nests that continue to row. If nothing else a good Mn. freeze (coming soon) will take care of them.
Automotive starting fluid.
Years ago I had a can (think it was NAPA brand) that killed angry stinging insects faster than anything. Dead before they hit the ground. The ones you miss catch a whiff and will go through the eye of a needle if that's what it takes to get away.
As the years went by, that can ran out so I bought another (don't remember the brand) and it was mostly ineffective for killing anything!
California has passed alot of laws regarding VOC emissions that has made alot of things that used to be good suck.
YMMV on what you have in yer state.