Is there any proof that kids do this? If so where?
What purpose does it serve?
I did find this which might explain the proporties of camel manure.
Either David likes to show off strange facts, maybe he inspired Stephen Fry. Or he has social awareness or he just likes the sound of the line.
Unless of course what he means is they put "camel shit" on the walls, as a form of protest. Like we would write "bull shit"