HEADLICE. 😷 Anyone have any home remedies?

My Daughter has very long, thick hair which she wears tied back every day.

The problem is as soon as we’ve got rid of the nits, she’s back at school and gets them again!

It really frustrates me, as it’s clearly the same parents who continue to not treat their children.

I also have 2YO Son with long hair and he gets them too!

1 1/2 - 2 hours they’re in the bath for whilst I de-flea them!

Does anyone know of anything to use to keep them away? I keep paying to get the branded lice killing liquids but it doesn’t keep them at bay. 😡😡😡