I have run afoul of an in ground yellow jacket nest when I ran over it with my gas powered weed whacker. They let me know in no uncertain terms they didn't want me around. I got stung a bunch of times as I ran yelling like a 6 year old girl would. I wanted to kill them with something that wouldn't poison my dogs, or the local wildlife. Dish soap was the magic.
I went back after dark, put a piece of screen door type screen over the opening and cut a small "X" in the screen. Then I dumped about half a bottle of Dawn type liquid dish soap into the opening where I cut the "X". Then put my hose over the opening and turned the hose on trickle and let it run all night. In the morning there were only a couple of very puny stragglers that would come out as I stomped the ground around the nest. Apparently any contact with the dish soap prevents them from "breathing" through their body and they die almost immediately. By noon I couldn't even get any puny stragglers to come out.
The next interaction was with a nest of yellow wasps in my plum tree that was about the size of a basketball. I waited until dark and took my hose with a very high power nozzle that was like a pressure washer, and two cans of wasp killer out to attack it. First I blasted it with the wasp killer, then blasted it with the water nozzle to break it open, then hosed the living crap out of it with the wasp killer. I kept rotating my attack until the core of the nest with all the larva fell onto the ground, and I hosed it down with wasp killer. I went inside as the remaining few tried to figure out if there was anything to attack.
In the morning I went out to see if there was anything alive, and there were no living wasps. The core of the nest with all the larva was on the ground and was only about 6 inches across...apparently, most of the nest was fluff and paper...but no living wasps and no larva moving.