Ugh, I HATE wasps, mud daubers, hornets and all their stinging relatives! I wage war with them every year. The most effective things I have found are 1)
fake wasp nests hanging nearby, 2) regular inspection for any nest building and immediately zapping at sunset when they are all back in their nests, then knocking down nest and stomping on it repeatedly (that might be a bit of overkill).
3) I use
Skill-it algaecide, not for algae but because it changes the surface tension of the water so When they land on it they sink a bit and can’t fly away, so they drown. VERY satisfying. The first time I used it a couple of years ago, I found about 20 dead wasps in the pool - it was great. Now I touch it up every week to two weeks. I don’t find as many because I think the wasp-word has spread and they no longer think of my pool as a watering hole.
4) Lastly, I keep pool net nearby especially if I am in the pool. If one tries anything, I grab the net and hold it under water until it stops kicking.
Disclaimer: If I see a honey bee trying to land, I scoop it and relocate it. I don’t want to kill bees, but I don’t mind killing their nastier cousins.