Pain is immensely enjoyable, which is why we indulge in it in a multitude of subtle ways. Including, for example, the need to feel we are right and others are wrong, which is a painful pleasure based in the illusion of separateness.

To answer your query, the most successful approach I have found is to provide a space in which the person feels safe to express themselves honestly. If they feel any sort of judgement, they will become defensive and trapped in their own turmoil. If one comes forward with an open, genuine, unconditionally loving heart, there will be little negativity for the other person to grasp onto. In this way one can facilitate the person in question's realization that they are the source of their own suffering.

Thank you very much for the in depth reply and questions. Also, kudos for realizing the triple entendre of my screen name :D I hope you have a wonderful day!