It is sufficient to perform one ghusl for both menstruation and sexual impurity, or for the Friday prayer and the ‘id prayer, or for sexual impurity and the Friday prayer, if one has the intention for both of them. This is based on the Prophet’s saying, “All acts are based on intentions.”
If a person performed post-sex ghusl but did not make ablution, the ghusl will suffice. Said ‘Aishah, “The Messenger of Allah did not perform ablution after ghusl.” Ibn ‘Umar said to a man who had told him that he performed ablution after ghusl, “You went too far.” Says Abu Bakr ibn al-‘Arabi, “There is no difference of opinion among the scholars that ablution falls under the category of ghusl. If the intention was to remove sexual impurity, it also includes the minor impurities, as what sexual impurity prevents is greater than what the minor impurities prevent. The smaller one falls under the greater one, and the intention for the greater one suffices.”
It is acceptable for a person in post-sex uncleanliness or a menstruating woman to remove their hairs, cut their nails, go to the markets, and so on, without any dislike. ‘Ata said that such people can get cupped, cut their nails and their hair, and that this is allowed even if he (or she) has not performed the regular ablution. (Related by al-Bukhari).
One may enter a public bathroom. As long as he keeps his private parts from being seen, and he does not look at others’ private parts. Says Ahmad, “If you know that everyone inside the bathroom is wearing a loincloth, you may enter. If not, then don’t enter.” The Prophet, upon whom be peace, said, “A man should not look at another man’s private parts, and a woman should not look at another woman’s private parts.” There is no problem with mentioning Allah’s name in the public baths, as mentioning the name of Allah under any circumstances is good, since there is no text prohibiting it. The Messenger of Allah used to remember Allah under all circumstances.
There is no problem in drying one’s self with a towel or other cloth after performing ablution or ghusl during the summer or winter.
It is permissible for a man to use the water left over by a woman and vice-versa. This is derived from the fact that it is permissible for them to perform ghusl from the same container. Ibn ‘Abbas narrated that some of the Prophet’s wives were performing ghusl from a container. The Prophet came and performed his ablution or ghusl from it. They said to him, “We were sexually unclean.” He said, “The water does not become impure.” (Related by Ahmad, Abu Dawud, an-Nasa’i and at-Tirmizhi, who called it hassan sahih). ‘Aishah used to wash with the Messenger of Allah from one container, and they would take turns taking water until he said, “Leave some for me, leave some for me.”
It is not allowed to bathe in the nude in front of people. It is forbidden to uncover one’s private parts. If you cover it with some clothes, it is permissible. The Messenger of Allah would cover Fatimah with a curtain when she performed ghusl. If one performs ghusl in the nude, far away from the people, it is not prohibited. The prophets Musa (Moses) and Ayyub (Job) did so, as al-Bukhari, Ahmad, and an-Nasa’i recorded.