Now to kill the nest....Suit up...and observe. Find the hole and mark it. Locate the secondary escape hole. And mark that one too.
Walk into the house...."What the heck are you doin' dressed up like that? ....Oh no you don't! Don't be such an idiot." What if you get stung again? It only takes one." How can you be such an IDIOT? Next one could kill you."
"Yeah but the dogs go out there. Don't want them to get ganged up on do you? And what about the grand kids." "Yeah...I guess you're right. Just be careful...you dope. I did buy the stronger Benedryl yesterday. And the liquid is supposed to work faster, too. But if you get stung we're of to the hospital again. You can swig down the Benedryl on the way."
So I wait til after dark. Cover their holes with plastic, and weight it down so no escape possible. Hey...it worked on you tube I can see they are ready for a fight. But they can't get out. Cut a slit and plug with funnel with a good strainer. Pour in about a cup of Dawn dishwashing detergent. Followed immediately with 3 gallons of boiling soapy water. Then cover the hole. Few minutes later, flood with garden hose. See the water and larvae, and nest bits come up thru the secondary escape hole. A few suffering hornets too. But they cannot fly. The soap coats their wings.
Checked it out the following day. From a safe distance. Pretty much destroyed the nest. A big hole in the ground where the nest was. Some flyers buzzing around. Seems they weren't all at home last night. A few out hitting the bars, I guess. So I won't be mowing the lawn again out there for a while. Will watch them to see where they build their homes next. Who knows?....I might have another colony somewhere.
I can see this war is not over yet.