Kill them with fire.
bit dangerous ,, Petrol works especially if they are underground . A couple of litres down the opening and seal. all dead and hive useless in 2-3 days . Gets the adrenaline going i tell you .
I tried this with a big nest in a DOC camping area at Xmas. Doc had some powder which was not carbaryl - which does work - but some ersatz stuff which they changed to use because carbaryl is toxic and too persistent in the environment, apparently. Their stuff was useless, made the wasps drowsy for a few hours then they came back to life. Petrol didn't work either - I gave it two good dumps, but a couple of days later and it was business as usual.
Carbaryl does work - very effectively. Dump it in the entrance at dusk.
I hope this new system (Vespex) works. I hate wasps.