Just be bloody careful if you try to destroy a wasp nest on your own - I tried it once and after using insecticide, the nest appeared dead(the next day or so), I went to clear it up and it broke open, releasing many live, angry wasps and I was badly stung.
Multiple wasp stings can be life-threatening even to a person who is not sensitively allergic.
WD-40 will kill wasps.
Wasps are only on the lookout for food - they aren’t looking to go and sting people. I have a bad allergic reaction to stings but I won’t kill anything just for the sake of it. Apart from anything, you can’t kill them all - and why would you want to?
Here (at work) we put sugared water out on some waste ground. Within a day all the local wasps know that the food is there and don’t bother us anymore.
'Coz they’re little bastards and they don’t even make honey.
…and they always seem pissed off
So would I be if everywhere I went everyone was trying to kill me…! 
While your techique for dealing with the nest is correct, this statement needs to be clarified.
It is quite possible to have “just one.” They tend to move around a lot while foraging and if one finds a single wasp in one’s house, it is more likely to have come in the door with the groceries than to have emerged from a nest in the house. Thus, a catch and release policy for a single wasp trying desperately to find its way through a glass window is quite safe.
(Technically, there are also a number of solitary wasps that do not build communal nests, but they are not directly related to this discussion.)
Well I’m not surprised everyone’s trying to kill you if you keep running around in a silly jacket, stabbing people with a poisoned skewer sticking out of your arse!
Well, except that it’s such a hassle getting the bait on those tiny little barbless hooks.
Send them into combat.
like ** j. c. ** said, I think any liquid would work, but windex is handy since my wasps tend to hang around the windows anyway.
Cats are another story. I seem to have a mild wasp infestation in my attic. I’ve spoken with my cats. While they are fascinated with the wasps, they haven’t yet shown any interest in killing them.
-Lil