I think those of us that are lucky enough to not be allegic to bee/wasp/hornet stings just don't appreciate the gravity of the matter. If our yards were covered with insects carrying 9mm Glocks we would probably be calling for the legalization of DDT!
I think this sort of issue is one for a professional, "large" area abatement requires a fine line between enough and too much and I don't think that line can be defined by any of us (unless there are pest prevention professionals among us) or by the label on a BORG product.
Dirt (mud) daupers are wasps and thus can sting but it is rare for them to sting a human, but the location of their nests can be perfect places for hands to "grab" sight unseen. They can be a pain even for the non-allergic since their nests are not as easy to clean off as say a paper wasp but they eat a lot of spiders and LOVE black widows so I tend to tolerate them.
Honestly, even without any fear of death I wouldn't attack a wasp and certainly not a hornet's nest with water, you ain't gonna kill 'em and they will be right back at it tomorrow, that is after the calm down and quit hunting you!
Of all the laws Brandolini's may be the most universally true.
Deep thought for the day:
Your bandsaw weighs more when you leave the spring compressed instead of relieving the tension.