I personally think it is a horrible idea and really question why any therapist would attempt this. I had really traumatic childhood and it is NOT something I would want at all. How does it end? I just can't understand how it can end well. Eventually therapy will end and the therapist will be gone and it's assumed (I suppose) that by the time this happens the client will be healed enough to not need or want the therapist anymore, but I just cannot see how that would happen. How can you just not have someone in your life like that who has played that role? How will that not also be traumatic and painful?

I think it's awful. Hope it works for the people who try it, but I've seen it end badly here many times.