It sounds much like my own technique of holding a small iron hammer on a string attatched to the ceiling back and when you enter SP and let it go it swings forth straight against a large Bell.

This, however, failed to wake me up. I guess I'm too far out of consciousness sometime before my had enters SP and lets go.

Maybe I should get a bigger, Louder bell. perhaps one of those DAMN annoying, loud Schoolbells and a Large, heavy iron hammer to ring it. A bell that will CERTAINLY awaken me from my just initiated slumber. Thanks Dalí