The Book of Menstruation
3/13. Chapter:
It is recommended for the woman who is performing ghusl following menses to apply a piece of cloth scented with musk to the site of the bleeding
Sahih Muslim
وَحَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا شُعْبَةُ، فِي هَذَا الإِسْنَادِ نَحْوَهُ وَقَالَ قَالَ " سُبْحَانَ اللَّهِ تَطَهَّرِي بِهَا " . وَاسْتَتَرَ .
This hadith is narrated by 'Ubaidullah b. Mu'adh with the same chain of transmitters (but for the words) that he (the Holy Prophet) said: Cleanse yourself with it, and he covered (his face on account of shyness).
Reference : Sahih Muslim 332dIn-book reference : Book 3, Hadith 73USC-MSA web (English) reference : Book 3, Hadith 650