Shows like this and Don't Tell the Bride surely must be only capable of running for only one series as the surprise element is taken away. I know not everyone would have watched this programme first time around but if you were asked to guide someone through a days work closely monitored by a film crew you would have bound to spoken to one of your mates who might have a clue what was going on after seeing the show hence the best behaviour ... or am I being my ususal cynical self???
Actually , thinking about it , if the filming was done covertly , i dont suppose there would be a show - as i would guess that the bosses would not give permission for their company to be portrayed on national televison in a bad light