One of my own "Holy Grail" clips, is of the (already mentioned here) Grumbleweeds TV show. If anyone ever comes across it, please post a link here. The ep concerned was a Christmas Special of The Grumbleweeds show, and it featured Robin (the one who did the Jimmy Saville impressions), this time doing a more than passable Bruce Forsyth.
Basically, he kept ranting on about "the Turkey game", this being the forfeit that the "contestant" could choose if they didn't want to do some other challenge. To demonstrate The Turkey Game, they had one of the girls off the show (the dark haired girl, Mandy I think she was called) standing inside a booth, while "Brucie" kept rattling on about "the turkey game, the turkey game". They then tipped over the girl, "stuffing" (some dry grey powdery stuff) "gravy" (brown gunge) and I think they finished off with feathers. I seem to remember she let out a shriek, making me think she wasn't expecting the "gravy".
Anyhoo, it's been YEARS since I saw that clip, but it sticks very vividly in my mind (not least because I've looked high and low and not been able to find it again).
Just thought I'd mention it in case anyone else stumbles across it, as it was definitely worth a watch
