It is narrated from Umm al-Mu'mineen Sayyidah Aisha (may Allah be pleased with her) that she used to scrape semen off the garment of the Messenger of Allah (peace and blessings be upon him), and he would pray in it.
Hadith Referenceصحيح ابن خزيمه / جماع أبواب تطهير الثياب بالغسل من الأنجاس / 290