I've travelled in the cockpit. I don't like it, in fact I actively dislike it: certainly not anything I would ever request. But the flight was full, and although I'm not an airline employee (or related to one) I was travelling for an official body and after a standby discussion at the gate, the pilot intervened to invite me to use his jump seat. No paperwork at all.

It wasn't SWISS, but it was a major EU carrier.