Here’s what you need to do:
-Use a good amount of dishwashing liquid in a hose-end sprayer, about 1/4 cup.
-Get the water going until the suds begin.
-Blast the nest from as far away as you can be (bee? ha!) while still maintaining a powerful spray.
-Do the deed in the evening (dusk or later) after all the wasps have come home for the night.
-And wear long pants and sleeves, just in case…especially if you have low water pressure.