First, comb through dry hair with a normal comb to remove any tangles. Shake the bottle and apply the solution to dry hair by spraying close to the root. Ensure the entire scalp and hair are fully coated with the solution. Massage in and leave on the hair for 10 minutes. After 10 minutes comb through the hair using the fine metal toothed Full Marks Removal comb provided to remove dead lice and eggs. To ensure a thorough job, divide the hair into four quarters and comb each separately.