What you say
"Swearing is about losing control, and one of the key things schools have to teach children is how to control themselves. Children swear a lot. They think it's a cool, adult thing to do, as their role models - footballers, pop stars - tend to swear a lot. They need to ask themselves that if they swear a lot too, will that have negative consequences? If they swear so much outside school - or at home - that they cannot stop swearing in school, they need to be shown that, in the long term, it will have a negative impact on their life. If you go for a job and you swear in the interview, you've blown it.
"Also, constant swearing signals poor vocabulary and therefore a lower IQ, and will lead to other people being unimpressed. If I use unusual words in my conversations, if I have a wide vocabulary, that tends to signal a higher IQ and gives a positive impression of intelligence. Children need to know this."