I know that activated charcoal can be fed as a poison antidote I believe. Don't know who or how much but I think ti can be used. @Eggcessive @Wyorp Rock @azygous
I copied this off there website, it is not safe.
Hazards to Humans and Domestic Animals
CAUTION. Harmful if swallowed or absorbed through skin. Avoid breathing vapor. Avoid contact with eyes, skin or clothing.
Here is the link to website, look under the precautions drop box...
Did he feed them chemicals, ir jus DE? DE won't kill them, but can cause problems if it is consumed in a large amount. Do you have a link to the product he fed them?