I have no insecticide phobia, I just like to keep things to a minimum. Re. borax, I think it's great stuff, just not food.
The EPA gets rather vocal about the chalk...
Insecticide Chalk | Pesticides | US EPA
... and I can see their point about labling and kids. Not much of a concern for retired cruisers.
Wiki on the other hand said it "contains the pesticides deltamethrin and cypermethrin" and "Despite its illegal status, 'Chinese Chalk' is still imported from China and sold in Chinatowns in the United States. Worldwide, the product remains very popular due to its effectiveness in rapidly controlling crawling household insect infestations without fumes, foul smells or sticky toxic residues, and its relatively low overall toxin content compared to other insecticides."
The ingredients seem to be thought relatively safe.
Deltamethrin - Wikipedia, the free encyclopedia
Cypermethrin - Wikipedia, the free encyclopedia
These are used in the US. Thus, it is only the packaging that the USEPA hates, which makes sense. Seems like a good product to me, specifically because application can be so well controlled.