The saying of Allah Almighty: "And if you are in a state of janabah, then purify yourselves thoroughly." [Surah al-Ma'idah: 6]
And in the hadith of Sayyiduna Imran bin Husayn (may Allah be pleased with him), the Messenger of Allah (peace and blessings be upon him) said to the junub man: "Go and pour it (the water) over yourself."
And in the hadith of Sayyiduna Abu Dharr (may Allah be pleased with him) he said: "When you find water, let it reach your skin."
And he (peace and blessings be upon him) did not order him to observe any sequence (in the bath).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / Q870