When purchasing this product, it is important to remember that this is rated for home use, indoors and out. When I read reviews that say that this did not instantly kill a spider when it was sprayed, I want to reply and say 'you are expecting the result of arsenic'. Well, you don't want that effect, because imagine what that would also do to your pets, kids and others that may come in contact?
As I have used this over the years, I've learned that you have to be patient with this product and use it exactly as it is recommended. This doesn't necessarily kill bug instantly, but rather creates a constant deterrent zone where new bugs do not want to enter, and makes existing bugs want to leave. For example, I live in an area where ants and 'hobo' spiders are a big problem. In the spring, I spray a wet, constant perimeter around my home (in garage, window wells, etc). After a few days, I notice that the window wells are free of spiders, and the ants are no longer marching in through the cracks. After a few weeks and into the summertime, I keep reapplying as directed. In the fall, when the bugs want to come into a warm home, I keep up the applications. I stop only once the weather starts freezing. If I remain consistent, and keep the area 'protected', this product is extremely effective. Bugs do not like this stuff. Again, this is a home-grade product, and because of the safer nature of the formula, the results may take a little time as the pesky bugs pack up and leave. Apply the spray effectively, inside and out, and you'll see less and less bugs until they are gone. And it does not smell nearly as bad as some of those old bug sprays you may remember when you were younger. Once it dries, it's pretty much odorless.
The best part of this product is that it is as effective as your neighbor who just paid Mr. Orkin 10 times what you spent, for the same results. I've been using this stuff for 8 years, and know that it works, while not worrying about the toxic effects of chemicals in years past.