We should not say things like a person ate human feces or drank urine in order to gain ground.
While I am sure these things do happen it is not really something that you should say about a stranger just to score political points.
It’s uncivilized and it forces people to have conversations that are unbecoming. Also, when people say these things make sure to correct them. Then tell the person that it’s being said about.
Most liars will stop once you get everything out in the open.