yellow jackets nest
The safest way is to wait them out as they are at the end of their season and the freezes will kill out the colony. Quick killing insecticides sold over the counter work well, but that doesn't seem to be your option of choice. A couple of 5 gallon buckets of soapy water (dish soap) poured into the hole in the ground quickly at night will drown them. But do not hold a flash light when doing this as they will be attracted to the light and potentially sting the person with the light.
My best recommendation is to wait them out. This winter you should fill in the hole so a new nest does not use that hole next year.