Re: spiders around exterior of house
i use to work for orkin pest control im here to tell ya spiders will never go away you may kill a few. the problem with them is they do not absorb pesticides thru there legs or body most pesticdes work bye absorstion of a pesticide into the central nervous zone killing the animals such as roachs . spiders on the other hand dont so unless you directly spray them with a harsh chemical. there not gonna die. i use starting fluid around my house when i see a large spider. but the amount of eggs layed by spiders. were all domed to be taken over .

desiel fuel will work sprayed outside killing spiders and everything alive with a lasting residual. no smoking please.
Thats the problem, you worked for Orkin. I have been an exterminator for 9 years. I can spray a lake home twice a year and they will never see a spider. I spray my own place once a year and never see anything. The big companies are all about profit, my company is about service. I take business from the big companies every day using superior products and superior service, and no contracts.
BTW, spiders do absorb through the soft tissue sections between joints and exoskeletal segments, and through the mouth parts when grooming. What does not work well is foggers because arachnids have book lungs that can be closed off, whereas insects cannot close off their respiratory system. The very best types of chemicals for spiders are micro-encapsulated, but plain old Permethrin or bifenthrin works fine. I have watched hobo spiders cross aged, dried permethrin and die within a half hour...