Pranarom's Aromavita 99 is a blend of Tea tree, Lemongrass, Clove and Peppermint essential oils. I have used it for lice prevention but I bought too many bottles. I have two 10 ml bottles for sale, unopened and in packaging. Each are $10 or both for $15.
Can buy at Optimum Health for $18.38 a bottle,
Add 5-10 drops to shampoo and leave for 5 minutes on scalp.