(a) Sayyiduna Abdullah bin Umar (may Allah be pleased with him) said: The prayers were fifty, the ritual bath (ghusl) for janabah was seven times, and washing urine from a garment was seven times. The Messenger of Allah (peace and blessings be upon him) kept asking, until the prayers were fixed at five, the ritual bath for janabah at once, and washing urine from a garment at once.
(b) It is reported from Imam al-Shafi'i (may Allah have mercy on him) that the Prophet (peace and blessings be upon him) said: "Under every hair there is janabah, so wet the hair and cleanse the skin."
This is not established.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 848