Pimhole is an area of Bury, just off the M66. More relevantly though, it was used in a Fry and Laurie sketch way back in 1990 as a fake swearword. The joke was that the BBC wouldn't let Fry and Laurie swear on the telly, so they'd had to make up their own swearwords, like pempslider, frunk, fusking and pimhole.
Earlier this week we carried out a poll asking about attitudes to swearing on the television and asking people which words they thought were acceptable before the watershed, which should be limited to after 9pm and which were totally unacceptable on the television (for more about the general results and attitudes to swearing see this article). As an experiment, we also added one fake swearword - pimhole - to the list to see how people would react.
25% of people, naturally enough, said they didn't know. A further 14% said that it would be quite alright to say pimhole on the telly before the watershed (I have no idea how many recognised its provenance or suspected it was made up). However, 38% of people thought that pimhole should only be broadcast after the watershed and 23% thought it should be totally banned on the television. The survey suggests pimhole is regarded as being more offensive than words like bollocks or bastard.
There are various explanations why - I expect the main reason was context. The question was all about bad language on television, and pimhole was included in a list of swearwords including some that are considered extremely offensive. It's likely many respondents assumed that pimhole must, therefore, be a swearword. The very fact that people hadn't heard of it may have lead them to assume that it was particularly crude or offensive.
It's also possible respondents may have been guessing what "pimhole" might have meant and coming up with very offensive meanings (and after all, the point of the original Fry and Laurie sketch was that the fake swearwords did sound as it they might be very rude). In the 20 years since the Fry and Laurie sketch, the urban dictionary even has entries making assumptions about exactly what Fry & Laurie meant by pimhole.
It goes to show that what is a swearword is very much down to context - put an innocent word (admittedly one that sounds slightly rude) in the context where you find swearwords and a significant minority of people assume that it must indeed be something obscene.