We used to dip spitballs in alum and aim for the other kids mouths. That way when we hit the bulls eye (target) and it went in their mouth...they couldn't rat on us...their mouth couldn't open...it was drawn shut. And also dip the spitballs in cinnamon and when it hit their eyes...they couldn't see "Who Done It" from the stinging/burning effects. Plenty of entertainment without YouTube to view it on...we just relied on witnesses to pass on the info.
Don't remember any stabbings...only thumb tax set in peoples chairs and when they sat down, they launched upwards towards the ceiling only to come back down.
Those were the days :->