I've read that to stop harming, but to still get a release and that feeling that S.I. brings ( I don't know what that is, I've never S.I. and don't understand what it does, feels like, or why the need to do it) but if a tight rubber band is placed around the wrist and 'pinged' when the need to S.I. arises. The snap of the band against the skin hurts, but does not cause an injury. The sensation is said to be the same. Would that help to try ?
Best wishes x