I get so frustrated when products are promoted because they contain "natural" ingredients and so are supposedly safe. Yes, pyrethrins are plants, I think they are related to crysanthemums, but that puts them in the family compositae which contains other toxic plants.

Anyway, I checked into the ingredients for Stratchex and it contains as much permethrin as pyrethrin. This on permethrin:

Permethrin, like all synthetic pyrethroids, is a neurotoxin. Symptoms include tremors, incoordination, elevated body temperature, increased aggressive behavior, and disruption of learning. Laboratory tests suggest that permethrin is more acutely toxic to children than to adults.

So, not something you want on pets that belong to children.