Hanging only kills by suffocation if you do it wrong. Stupid kids can't even hang themselves properly.
...(rant on the state of modern education to follow)...
Yeah. If they read the right medical journals, they'd know the best way to manage it is a "long-drop" hanging--dropping from greater than body height. "Short-drop" cases have an excellent prognosis as long as the suicidee is still alive by the time they reach the hospital.
On the whole, I'd prefer they do it this way rather than guns since they're more likely to botch the job!