The story goes something like this, Shiva/Shankar/Mahesh(https://en.wikipedia.org/wiki/Shiva) is a god of destruction in Hinduism. When he was out in the forest, his wife Parvati was alone and had to go for a bath. But she was concerned what if some stranger gets into the house while she was bathing. So to prevent anyone getting into the house she removes the layer of sandalwood and turmeric paste she had applied to her body and makes an idol of a boy and puts life into him. As the boy comes to life she instructs him to guard the house and not let anyone enter while his mother(Parvati) is having a bath.
Her husband returns after a while. Parvati is still in the bath. And as he tries to enter the house, the boy prevents him from doing so saying that his mother has instructed him not to let anyone inside the house. Shiva, known for his temper, gets angry and throws his weapon, trishul(trident), at the boy which chops off his head and it falls somewhere in the forest. Parvati, when she returns from her bath sees the headless body of her son and gets angry at Shiva and demands that he bring the boy back to life. But there is a problem, the head is missing. So Shiva goes in search of the head into the forest but he is unable to find it. So when he sees an elephant in the forest, he chops off the head of the animal and attaches it to the boys body and puts life back into it. That is how people of HN, the Hindu god Ganpati got his elephant head :)
Now, did I mention this is a mythological story? So please be kind to this gentle soul. I only narrated this story because it includes the concept of bathing :D
There are lot of such stories in Indian mythology where there is mention of bathing.