Wish I could help Jelly, but I've never had lice. Just a thought though, if you smeared all over where the lce are with vaseline or equivalent, would that suffocate them?
And someone mentioned tea tree oil for something was that lice? you could mix it in with the vaseline. I say vaseline, but that's a name isn't it? I just buy the cheap petroleum jelly but don't know if you can get it out there?
When my dog had ticks when I lived in Malta, we used to dab a little meths on them and it killed them. they used to jump off the dog too, but I don't suppose you can do tha with lice, they are smaller!!!