Ashcombe
I know a couple who were contestants on it and they were absolutely forbidden to approach Alexander Armstrong or be within a certain number of metres of him!
Once defeated, they were unable to mix with any other unsuccessful contestants. They had to take a few different outfits so that the wardrobe mistress could see what would look best against the colour of the set. This particular couple were winners but were forbidden from telling anyone at all before the recording was aired, especially on social media, on pain of the prize money being withdrawn.
Oh, have gone off Armstrong now, I mean of course he doesn’t want to be mobbed by contestants wanting his autograph but that sounds a bit much.
Personally have seen a few famous types when out and about visiting family in London but I give them a wide berth, not for their sake but because I don’t think I would have much to say to them and vice versa. They are just strangers. The only famous person I did meet with my starry eyed daughter who was studying Astro physics, was Stephen Hawking at Cambridge, he was a sweetheart, very patient and had a wicked sense of humour.