Im in the same situation in Essex I’m hand squatting wasps and hornets whilst inspecting managed to hand squat 15 hornets this week plus tons in traps always see a few hovering around the apiary.
I was told several drops of flea programme mixed with cat food or corned beef is a good way to knock a few off when they go back to neat so I’m going to try it this week
I have no issues with hornets normally but had one dive straight into a Nuc when I took roof off and it was balled instantly and helped dispatch it with a firm press on its head.
My bees are more important to me than any hornet or wasp if that means I’m a ignorant person so be it