Incredible...the things you find out on here...wiki spakes thus..
Swearing
The non-worded but scored script seemed to allow the Clangers to say almost anything, including swear words in the basic script. As part of the production, Smallfilms had to send the scripts to the BBC, and on reading the script for episode three they asked Postgate to remove some "Clanger-speak", explaining that, although whistled, "you can’t say that on children’s television [...] you just can’t". At the opening of the episode, before a rocket shoots down the Iron Chicken, Major Clanger kicks a door to make it work, and his first words are "Oh, sod it; the bloody thing’s stuck again". Postgate replied that viewers wouldn't recognize what was said, but the BBC replied "But people will know!" The offending Clanger-talk remained in the episode, and after the series became a commercial success, and the Golden Bear Company became responsible for merchandising, the Clanger-talk used for the talking-squeezable model was this phrase.
My deepest apologies Viv...I will try and make up for it...
