I'm not qualified to judge whether or not it's true, but if you actually read the article, they address this concern directly: Boric acid is much less expens

I'm not qualified to judge whether or not it's true, but if you actually read the article, they address this concern directly: Boric acid is much less expensive than Spinosad. It is also about as harmless to humans as table salt is. It is a chief ingredient in Silly Putty. Dr. Schlein said he had heard that some Malians sampled the alcoholic bait brew, with no ill effects. But it kills insects that eat it. It is common in cockroach control; when a thin layer is spread on floors, cockroaches take it in when they preen their feet. “You can buy it by the truckload,” Dr. Christensen said. “And it kills in so many ways that there’s never been resistance to it. Some authorities think there never will be.”