I've got a silverfish and cricket problem in the house. I've read
that diatomaceous earth is good for killing insects.

But I saw some sites say that if you breathe DE, then you might have
serious lung problems. Then I saw some sites say that there are
different types of DE - you want the "food grade" type, which
apparently is safe for humans, and is even used in flour and
Bisquick. Is that true?