This is one problem all School going children face in life.
Take 2tblspns of Vinegar and dilute with 2 tblspns of water. Apply and leave for an hour before washing well.
Take a cup of Coconut oil and add 1 tspn of crushed Camphor to this. Heat the oil till camphor melts. Apply well on scalp while the oil is still warm. Leave for 1 hour before washing.
Make a paste of Basil leaves. Drape a towel and leave overnight or at least for 2 hours. Wash.