Okay, so my attempt at killing the wasps with wasp spray didn't work. Onto my next attempt. I have decided that the next thing I will try is to squirt charcoal lighter fluid into the hole from which the wasps are coming out of the sod. Last night I removed the rest of the cabinet, except for the thing backing piece that fell off as I was taking out the rest. I figured that I had likely already disturbed the yellow jacket nest, so I waited until early this morning to pull out that last piece.
That leaves the lighter fluid for tonight. If that doesn't work, I have thought of another, even more dangerous option (danger from the wasps). I will try to fill the hole with canned foam. Sticking that nozzle in there is what's going to be dangerous, so I'm hoping the lighter fluid works.
And if you hear about a guy getting stung dozens of times, you'll know who it is.