One of us would have a shirt in which she would menstruate and in it she became sexually defiled. Then if she ever saw any drop of blood in it, she would rub it off by applying her saliva.
Sunan Abi Dawud Book 1, Hadith 364
← Previous Hadith I asked the Prophet (ﷺ) about the blood of menstruation on the clothe. He said: Erase it off with a piece of wood and then wash it away with water and the leaves of the lote-tree.

Sunan Abi Dawud Book 1, Hadith 363 Next Hadith → Messenger of Allah, I have only one clothe and I menstruate in it, how should I do ? He said: When you are purified, wash it and pray in it. She asked: If the blood is not removed, (then what) ? He said: It is enough for you to wash the blood, its mark will not do any harm to you.

Sunan Abi Dawud Book 1, Hadith 365