Wasp sprays tend to be able to shoot 10-20 feet precisely so you don't have to get too close. I've used them for various sorts of nests, and they've done a good job. Also, wasps and bees are less active/inactive at night, so spraying after the sun goes down means you're far less likely to be swarmed. I recommend wearing clothes with long sleeves and legs, anyway, just in case.