It sounds like you have a real delema on your hands. I would have tried the spray first and that they came back is not a good sign. I can empathize with you as I had my "spot" invaded by a nest of hornets this fall. It is a basket size nest and only dangling by a thread. There was no way that I was going to mess with them so I moved my "spot". If I go there in dear season and it has been cold enough that nest is coming down!