I want to kill the insects and spiders living in my egress using something non-toxic to humans, dogs. I was thinking copious amounts of salt would kill earth dwelling bugs and what appears to be ground spiders with funnel like webs. The insects seem to be majorly silverfish. I am in Missoula Montana.
I think the bugs are coming from the egress. Here's an internet photo similar to my egress. The ground at the bottom is the area in question.