I would get a wad of loose newspaper, put on the end of a pitchfork, pour kerosene on it, light it...... and hold it directly under the nest which will instantly burn off their wings, while also not catching the deer feeder on fire (arent they usually metal?)
How about some ideas from a guy that is allergic to bee/wasp/hornet stings?
Makes me pretty sneaky when I'm ridding myself of these little but potent pests!
Instead of risking serious stings and setting things on fire,
Why not just make a baited trap and trap the little buggers?
There are many commercially available traps on the market, or you can easily make one out of a 2 Liter plastic bottle simply by cutting the top off and inverting it like a funnel,
and taping it down to the sides of the bottle.
Then simply putting some sugar water (brightly colored sugar water works best, bright yellow or red) in about the bottom 1/8 or 1/4 of the bottle.
Hanging the bottle will make it more effective and keep it away from ground dwellers that might want a sweet drink,
Some people add poisons to the mix, but that is overkill and you might poison that big buck you are wanting to bag this year!
When the hive is trapped out (you stop getting hornets in the traps)
Then you are probably safe to use something like 'Ether' (starting fluid) that kills bees/hornets instantly on contact and evaporates quickly and toxic free,
Or brake cleaner that kills bees/hornets instantly on contact and dries quickly and toxic free to saturate the nest with before you try and take it out of the feeder.
I wouldn't use an actual Flying Insecticide to spry up in the feeder unless you have some way to wash it out afterwards... That might transfer to the feed for the critters you are trying to lure in, and you don't want to be eating the meat after they have eaten the poison (even if it didn't kill them, how about YOU!?)
To keep the little ba$tards out in the future, hang a bag of moth balls inside on the lid where they won't come into contact with the 'Deer Chow'.
Just the fragrance will make them do a double time out of the area for someplace more hospitable!
Don't forget to replace the moth balls every couple of months during nest building season, which depending on how far down you live in Texas, might be all year around!