Got LICE in your teeth? How about COCKROACHES? If so, you may want to apply some sodium fluoride to your teeth!
Sodium fluoride kills these little creatures. That means it is a poison, right?
A previous generation, in 1917, knew it and stated so publicly in newspapers.
source:
Dakota County Herald Jun-21-1917
full page
What would they think if they saw people today adding insecticide to their water and toothpaste?