There were other ways of making this dream a reality. I don't have a copy of the Algerian Air Laws manual to hand... Though I assume it cant be too far removed the the US FARs. Part 135.115 and part 135.115 make it very clear in Black and white that nobody other than crewmembers, check airmen, representatives of the FAA/NTSB etc may occupy a pilot seat or manipulate the controls during flight....
.... It seems a little maddening that the company appears to have set this up and nw is not backing the pilots... however, it is still down to the pilot to perform the flight in a legal manner, or refuse the briefing/gig.
No opinions are given here either way on whether or not this was a kind gesture. Just pointing out the relevant FARs and do understand that they may be different in other parts of the world... however, it appears that the Algerian authorities seem to agree with the FAA FARs here.