May have changed since the 70-80s, but the Swiss are/were more civilised. After the paperwork is done, the entire episode has to be videod, in which the doctor places a glass containing a lethal dose of barbiturate or whatever within reach of the patient (used to be with a prior dose of antiemetic), clearly explains what it is and what will happen to the patient if they drink it, and it's down to the patient to effectively commit suicide. Probably more complicated if the patient is physically or mentally incapacitated.

Then there follows a postmortem hearing/tribunal to establish that the clinic carried out every aspect of the process from first contact to disposal of remains in accordance with the rulez.