In article , gnx52
@alltel.invalid.net.i says...
Real Kill Wasp & Hornet Killer does a great joib on instant killing.
Contains tralomethrin and d-trans allethrin. It is aerosol spray. Too
dangerous to get on ladder when at war with hornets. Anyone know
of water soluble compound that is equally effective that I can apply
with my pressure washer from the ground.
Frank
Georgia

I've had good success by dusting the flighthole with Carbaryl late at
night. Two days later there were no live wasps left. I believe it's
water soluble.

-P.