A half cup of gasoline splashed up on the nest kills them in seconds. They will just drop to the ground. The gas evaporates quickly although I would pick up any dead wasps before the chicks go to them. A good spray of ether will kill them too with zero hydrocarbons left.
If you want to trap them a good bait is lacquer or lacquer thinner. When I spray cabinets during the spring to fall you have to watch for the drunk wasps, they love the spray booth when you are spraying, fly in wobble around a bit, then fall down drunk. If you are lucky not on your head or down the back of your shirt. Yellow jackets, red wasps, they all love the smell of lacquer.