Using an anesthesia drug (Propofol) as a sleep aid is at least negligent and likely malpractice. To use it without life support equipment available makes it a recipe for disaster. One of the most common side effects of Propofol is hypoventilation (life threatening lack of oxygen), which if not treated can result in death. Propofol is administered as an IV drip, so it is unlikely a patient can easily self administer. Doesn't look good for Dr. Murray...
I just had surgery where Propofol was used, and I can attest from personal experience that it is extraordinarily fast acting. I am in the medical business and understand what happens in the operating room. I watched the anesthesiologist inject the Propofol into the IV bag and saw the first few drops of the milky white solution drug start to drip...then it was "lights out"! It is a fantastic tool for surgery, but lethal in unskilled hands.