You can but lice treatments from your local pharmacy. Just follow the instructions that are on the box. You may also want to pick up some spray and make sure to spray anyplace that you can not wash. For example the car, car seats and things like that. You also will want to sterilize all hair accessories, and wash all pillows and blankets. If the lice have become really bad, you can always call your doctor as there is a prescription type head lice killer.