Get one of those mosquito zappers, and turn it on right next to the hole, leaving it on day and night. It annoys the hell out of them on their exit and return and the humming draws them out of the nest all night. You will clear 99% of them out in 48 hrs, done it heaps of time. We also had a big nest between the brick and plaster board in a cupboard. I bought a couple of the pressure can wasp spray, drilled a 3mm hole above the nest and saturated the nest, sealed the holes up in the process with duct tape. Its a bit stinky for a couple of days, and if you drill the hole too big, as I did once the wasps try to get out even with the spray nozzle in place. If its outside, kero, metho and petrol with a dose of engine oil provides the right amount of heat and soakage to burn the paper nest out of the ground and get the larvae. Baygon powder works well, especially in red gum sleepers. Yeah, I hate the pricks.