Asma bint Abi Bakr (may Allah be pleased with her) said: I heard a woman asking him (peace and blessings be upon him) what a woman should do with her clothes when she becomes pure from her menstruation. He (peace and blessings be upon him) said: "If she sees blood on them, she should scrape it and wash it, sprinkle water over the rest of her clothes, and pray."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4107
It is narrated from Sayyidah Aishah (may Allah be pleased with her) that when one of us menstruated, after her menstruation ended she would remove the blood from her clothes, then, after washing them, sprinkle water over the whole garment and pray in it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4108