Drenching a person's hair in thick oil, such as almond oil or olive oil, is thought to suffocate head lice if the routine is repeated daily for at least a week, according to Healthline. Mixing thick oil with an essential oil is also thought to kill lice.
An essential oil mixture should be applied to the head with cotton balls and left overnight or for a period of at least 12 hours, to have adequate time to work effectively. Examples include tea tree oil, peppermint oil, neem oil, lavender oil and clove oil. Only between 15 and 20 drops of any of these oils are needed in a mixture of 2 ounces of olive oil. The same measurement of an essential oil can also be mixed with 4 ounces of rubbing alcohol as an effective solution. If this mixture is used, Healthline recommends applying the solution with a spray bottle rather than with cotton balls. After applying the oil, combing the hair removes the lice.
Some essential oils are strong enough to cause an unwanted allergic reaction on the skin, so it is important to test a small amount of the oil on the hand before applying a large amount to the whole head. If an allergic reaction to any of these oils occurs on the hand, Healthline recommends trying another of the suggested oils until one is found that does not irritate the skin.