Going off on a bit of a tangent here but I just noticed something. In my recent post, I mentioned that I called T this past weekend, as a way to stop cutting. In session I had told him that I feel as though cutting is somewhat of a violation of our relationship. In essence, I am trying hard to remember and rely on the relationship as a way to stay safe. In a recent session when I was dissociating and very, very upset, T just kept saying "stay with me." So what I do is try to conjure up his voice and that moment when I am feeling unsafe, whether it's an urge to cut or simply feeling very anxious.
Pink, this is very similar to what you initially proposed in your post and I thank you for the positive influence. It's actually brilliant, if you think about it. But it requires really going into the relationship and accepting it and holding onto it. I can't always do that but I will say that I feel so close to him today.
If the relationship is honest and true I think that this is the best path to stopping si'ing. It brings the human side into the forefront.
So, I think you have an awesome T and the "good enough" mother will always listen to her child before mandating punishment.
Peace