Steve, I don't grok your comment:

But they are not dirty words[...]. In fact, they go back many hundreds of years [...]

How does the age of a word relate to its foulness? Fuck used to be the *polite* word; when the Norman term became polite, the previously-polite Saxon word became rude, and the rude Saxon term was lost to English. It seemed you were arguing that if a word is old its usage can't be rude...?