The way to kill a Yellow jacket nest is to simply place a clear bowl over the hole in the ground. Do it at night when they aren’t active. They won’t dig around it, but when sun comes out they get confused that they can’t come out. In several days they starve to death. No chemicals or fire.
For the yellow jacket sting, simply take a raw onion and slice it. Place the slice of onion on the sting and you will feel instant relief. The swelling will go away and you won’t have a mark after 30 minutes.