Hi Dave,
Yes I have used detergent solution to kill yellowjacket nests.  Around here the german yellowjacket is most common but we also have several other native species and detergent solution works on all of them.  I have sprayed them at the entrance and it does kill them but they crawl around for a while but best results are from pouring a large quanty of solution down the entrance hole to flood ( completely saturate ) the nest.  It sounds like either you didn't use enough detergent and/or sprayed the outside of the nest and didn't get the inside saturated as it is a contact material the insects have to get enough on them to kill.  It also works well for killing honey bees and is recommended to be used on AHB swarms in some situations as it does not cause the "flare up" reaction some insecticides do.

FWIW

blane


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Blane White
MN Dept of Agriculture
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