Try taking a stick and knocking them down. Or conversely pick up a bird and aim it over your head lol (hubby has joked that I should try tying a bird to a long stick to "extend" the reach and then holding it over my head :p). My flock knows when I'm helplessly waving a stick in the air that...
No reason to spray spiders (and I have severe arachnophobia). Chickens are happy to eat them. If you leave them alone they'll just take out other insects for you.