I say, and with God's guidance: There are two requirements for washing: First: Washing the mouth and nose: that is, rinsing and inhaling water; as He, the Exalted, said: {And if you are in a state of janabah, then purify yourselves} Al-Ma'idah: 6: meaning purify your bodies, so everything that can be purified must be washed, and the inside of the mouth and nose can be washed, as they are washed both as a habit and as an act of worship, recommended in ablution and obligatory in janabah. Second: Washing the rest of the body: not rubbing; because rubbing is supplementary and thus recommended. It is necessary to ensure that water reaches the roots of the beard, as well as to wash any hair that extends from it; there is no harm in this, and it is obligatory to wash the navel, mustache, eyebrows, and the external private parts of a woman; as narrated by Abu Huraira, Ibn Abbas, Abu Ayyub, Aisha, and others, with similar wording, he (peace be upon him) said: "Under every hair is janabah, so wash the hair and cleanse the skin," in Jami' al-Tirmidhi 1: 178, Sunan Abu Dawood 1: 65, Majma' al-Zawa'id 1: 272, Al-Haythami said: Its narrators are the narrators of the Sahih, and Musnad al-Rabi' 1: 16, Musnad Ibn Rahwayh 3: 964, Musnad al-Shamiyeen 1: 416, and Musnad Ibn al-Ja'd 1: 35. And from Ali (may Allah be pleased with him), he (peace be upon him) said: "Whoever leaves a spot of hair on his body from janabah that water does not reach, he will be punished like this and that with fire," in Musnad Ahmad 1: 101, Musannaf Ibn Abi Shaybah 1: 96, Sunan al-Bayhaqi al-Kabir 1: 227, Sunan Ibn Majah 1: 196, Al-Mu'jam al-Saghir 2: 179, and Al-Ahadith al-Mukhtarah 2: 74. See: I'la al-Sunan 1: 180, Fath al-Qadir 1: 50, Sharh Ibn Malik Q8/A, and Majma' al-Anhar 1: 21, and Allah knows best.