Leave lice treatment on hair as directed, rinse out. If you've tried over the counter lice treatments recently and feel it's not effective, try alternative methods: Apply mineral or olive oil to hair, leave on 30 minutes, wash out with Dawn dish soap.

What kills lice instantly?

Smothering agents: There are several common home products that may kill lice by depriving them of air and smothering them. These products include petroleum jelly (Vaseline), olive oil, butter, or mayonnaise. Any of these products may be applied to the scalp and hair, covered with a shower cap, and left on overnight.

What is the strongest thing to kill lice?

Some lice are resistant to pyrethrins and permethrin. That's when it makes sense to turn to stronger prescription drugs, such as ivermectin and spinosad (Natroba).