A bit of an offshoot but, when they implemented the safety changes to aircraft brought about by the Manchester Airport fire tragedy, they filled a plane with volunteers and timed how long it would take them to disembark in the chance of a fire etc.., but because the volunteers knew that there was no real risk they were very polite with an 'after you' attitude for leaving the plane, which is totally the opposite of how people would react in reality - so, they offered a big cash reward for the first 5 off the plane - result; they got the answers that they required for the survey.
Maybe that's the way forward for a test event.