So in the world of disconnected events, there was a thread on FR not that long ago that talked about the mechanism of Boric Acid and Diatomaceous Earth in killing insects. It worked pretty much the same as moon dust, getting in the joints of the insect and tearing it apart.
I wonder how James Burke would treat this as an episode of Connections. /rhetorical
In my late parents’ youth, a mixture of powdered sugar and borax worked well for roaches and ants.
Here’s the topic you mentioned I think:
https://freerepublic.com/focus/bloggers/4070791/posts