You can easily just get a bottle of Tea Tree Oil and use your favourite shampoo.
Add enough shampoo for one use in your hand. Add 1-3 drops of Tea Tree Oil. Mix this together and wash your hair thoroughly.
You wil feel the oil working as a sensation of warmth or cold on your scalp. This is great regarding dandruff and psoriasis too, not only against head lice.
Tea Tree Oil is a strong oil that really stings if you get the mixture in your eyes.
It might be an idea to have an adult help you.
Wash your hair normally one time with ordinary shampoo. Rinse and dry your hair slightly so that it does not drip a lot. Use shampoo with Tea Tree Oil and massage it thoroughly into your hair. This should make a lot of foam that does not run everywhere . Let it stay for 2-3 minutes and rinse.
This should kill off most of the adult lice and some of the eggs.
Repeat this treatment every second day for 8 days and you should be free of this pest in a natural way. It is important to have the time span of 8 days so that unhatched eggs can mature and hatch and the newborn lice be killed off.
Some people are allergic to Tea Tree Oil.
Very few people are allergic to concentrations as low as 1-3 drops when washing your hair with shampoo.
If in doubt, then try a teaspoon of olive oil mixed with one drop of Tea Tree Oil and rub a bit onto your leg or stomach or similar bare skin. If it turns red after 10 min, then you might want to find an alternative cure regarding head lice.