I asked the Prophet ﷺ about menstrual blood that gets on a garment.He said, "Scrape it off with a rib, then wash it with water and lote-tree leaves."
حدثنا مسدد حدثنا يحيى يعني ابن سعيد القطان عن سفيان حدثني ثابت الحداد حدثني عدي بن دينار قال سمعت
سألت النبي ﷺ عن دم الحيض يكون في الثوب قال حكيه بضلع واغسليه بماء وسدر
Its isnad is sahih. Ibn Majah narrated it in the Book of Purification, Chapter on What Has Been Said Regarding Menstrual Blood Getting on a Garment, no. 628, and Nasai, no. 395, from the hadith of Yahya Qattan, transmitted through him. Ibn Khuzayma graded it sahih, no. 277, as did Ibn Hibban, no. 235.