Diatomaceous Earth (DE) does the job of killing intestinal parasites quite well. So does walnut shell extract. Hilda Clark did it this way, with the walnut shell extract.
We use DE to keep our horses wormed and free of parasites. We do not use Ivermectin. Ivermectin is harsh and not necessary. DE also works for people.
DE and/or walnut shell extract is a lot safer than tobacco. You want a sick session, try chowing some tobacco and then swallow it...turns little boys several shades of green.
:)
[no sneaking off to the home garden center]
DE also kills fleas in an excruciating, exquisitely painful way...it cuts them to shreds.
I used DE to worm my cats. Got rid of a giant horrible worm (probably tapeworm, I didn’t want to look TOO closely) that was making one old man cat very sick. I took it myself for about 2 months just in case. No change, so I was probably worm free already.
The garden kind is the food grade kind AFAIK. The bad kind is the “pool” kind.