Yellow Jacket nest removal

All summer yellow jackets whirred in and out of a hole they had made at the bast of a raise vegetable bed. It was not possible to mow near the hole because these stinging insects are reputed to be especially horrible. They look a bit like bees. But bees take a lot of bothering to g=finally sting someone. And when they do their stinger comes out of them and they die. No so with the yellow jacket. It is easily antagonized, will do anything to protect the nest and the queen. When it stings the stinger stays in its body; so repeated stinging is possible.
I am quite allergic to insect stings so I gave this nest wide beth while I tried to find out how to get rid of them. By happy accident I was at the fabric store one day and a man was there selling his honey. He told me how to kill them in the nest without getting stung. I used a lot of dish soap and water. then even more liquid laundry soap and water. This smothers them.
So, after waiting 2 months I decided to check this evening. It is really cold here and all insects should be asleep. These had been dissolved, I think. The nests were stacked in 4 or 5 layers about 2 cm thick. When I tried to remove and blip them they kind of fell apart like a tender cake. Not sure if you can see what the nests look like with their crumbly layer and the cells. It is made of a papery substance like wasps nests.
In spring I plan putting gravel around that raised bed perimeter to discourage hole digging.