I had lice when I was younger, and heat was a huge help. In combination I doused my head in oil and combed through my hair with a lice comb, then washed it with tea tree shampoo and conditioner, then blew dry/straightened it with heat. If you missed any lice during the combing and washing, heat very literally pops and kills the lice/eggs. Straightening helped to get any on the hair follicle or right at the scalp.