One unintended consequence of challenging your relatives is that they will begin to hate you. It will be a hate that seems to you to be entirely unjustifiable. You will assume that you have no recourse. If you take the position that you have no recourse, you will have destroyed your ability to reconcile your differences.
Instead, you should continue to challenge every sin that rears its ugly head. Challenge until there is nothing left to challenge. Challenge with the same passion that you hope they would use if you were the guilty party. Do so with the same love and respect that you hope they would accord to you, if you were the guilty party. Challenge them every waking hour until you begin to see glimmers of hope. When you do, you can relent for a few days, but you cannot give in until there is a complete turnaround.