Sahih Bukhari Volume 001, Book 006, Hadith Number 311.
Narated By 'Aisha : A woman asked the Prophet about the bath which is take after finishing from the menses. The Prophet told her what to do and said, "Purify yourself with a piece of cloth scented with musk." The woman asked, "How shall I purify myself with it" He said, "Subhan Allah! Purify yourself (with it)." I pulled her to myself and said, "Rub the place soiled with blood with it."