Sayyidah Aishah (may Allah be pleased with her) says: The Messenger of Allah (peace and blessings be upon him) would perform ablution (when bathing) from janabah (major impurity), then put his right hand into the water, then run it through the right side of his head, working it in among the hair; then he would do the same to the left side with his left hand, until the water reached the skin. Then he would pour water over his head three times.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 825