Why you should never insert objects into a person's mouth when they're having a seizure

1. It can interfere with the person being able to breathe.
2. It can cause choking to death should the person happen to vomit.
3. Causes damage to the person's teeth. 
4. You can get injured by the person having a seizure.
5. You can have a lawsuit placed against you by the person for physical injuries if you happen to insert anything that does end up hurting them.

Above all...it's a complete myth that a person can swallow their tongue.