Just because you can, doesn't mean you should though.
head lice are a medical problem, right? why wouldn't you want your kids to get treatment for this condition free on the NHS? it's like knowing that state education is free for kids in the UK - then getting begging letters from their schools or asking them to pay for textbooks... ...er
Its worth £10 but have to ask the NHS in person :/ mmm.
Some years ago I was in a chemist in Tunisia and another couple heard me greet the pharmacist in Arabic. The wife asked if I could explain to the man that her husband had headlice. 😁 You may not be surprised to learn that my very limited knowledge of the language did not include that. I did, however, manage to say in French that the man had fleas and the lovely chemist said "Oh, headlice" and gave him the appropriate stuff. I never found out if it worked. 😃
Nitty Gritty comb is £10+ - paracetamol is 30p - see the difference?