Well, I decided it had to be done, so I did it before I got the last replies. May have been overkill. The mix was like half detergent and half water!
In any case they were all resting when I did it just after the sun set and I was able to remove the nest. I'm not sure of the fate of most of the wasps because it was too dark, but a couple ended up in the jar I was using. All I can hope for now is that any survivors don't try and rebuild. I appreciate the replies. If I'd been more patient I wouldn't have wasted as much detergent! The nest was about an inch and a quarter with what looked to be 10-12 wasps. These particular ones don't build huge nests, but they make up for it with their nasty tempers and painful stings. I have other varieties that are much calmer, though when they sting it hurts just as much per wasp. Unfortunately these smaller bad tempered ones tend to manage to give you more than one sting when they feel threatened. And they feel threatened if you walk within 10 ft of the nest!!
Edited - spelling correction