I think some T's use it informally. I know mine does in times of crisis with me... Currently, I have conditional permission to self-harm if it means I will not make an attempt on my life. I have to have reached out for support from my T, my wife, or a crisis line before doing it. I also have to admit to it, and be as careful as possible. If I do it too much, or it no longer helps to reduce the sui urges, then I need to tell my T and we will make arrangements for me to go inpatient. It's not exactly the same theory as i think you are referring to, but kinda close?

I wish I had the mental capacity to look at that site Perna put up, but I'm just spent.

I think harm reduction can go a long way in moving towards stopping in the end... I wish more hospitals/doctors understood it that way and utilized it...

I don't know if I'm making sense. sorry...