I think mostly what you can do is take care of your own half of the conversation, and hope they follow your lead. Thats what i did with my cousin last week. I tried to be open and honest and even apologized, but she had her agenda and was insisting on it, along with apologizing over and over. So i set a boundary. I asked her to reconsider what i said. I didnt criticize anything she said, except to ask, why didnt anything i said "count"?