When did these flights become "lessons"? I was always told that it was "Exercise 3: Air Experience" and that attempting to TEACH anything was a complete waste of the flight - as the person alongside you wasn't listening to a word - but just sitting there, open mouthed, at how different it was to be flying like a bird.
Absolutely, we ALWAYS got the "student" to "have a go" but it was always very very basic stuff (with you often secretly steering it with the rudder and trimmer) - but we never gave an EoC brief beforehand.
We just asked where they lived and/or worked and then tried to fly over that place to show them home from 2,000' if time allowed in a 30 minute flight.
Of course, all the patter about speed indications (but only so they could see how fast they were going) and altitude (for sake of interest when equated to fractions of miles instead of feet) went on - but nothing really educational.
First flight was meant to be pure pleasure and interest whilst deciding if you wanted to carry on for the full course - it was, as many have suggested the "shop window" for aviation training and the full PPL package was "sold" only if they enjoyed the flight. Their choice - no pressure.
One potential student that flew with us at Liverpool was sick as a dog and scared s***less when the instructor decided to demonstrate aerobatics to him on his "trial flight".
I absolutely agree that it should be a 100% honest "trial lesson" (for want of a better word) with a real potential student and not a sightseeing trip for a birthday present or whatever - one school used to charge for having extra passengers in the back seats - but it was never a full brief on the board before we went.
Lesson 2 (Exercise 4.1) was - absolutely - but not the "Air Experience" flight.