I don't know if this is an existing stretch and if it is maybe someone can tell me the name but this is what I've been doing. Sit on the edge of a chair or couch and reach under right leg with an ok grip palm down behind the glans and slowly stretch as far and intense as possible. Then take you left hand push down on your right hand. This takes the stretch to new level for me. Holding for thirty seconds and then switch sides and repeat.