There is no harm in it; we do it. Al-Khaṭṭābī (56) cited as evidence for the permissibility of this what was narrated by Abū Dāwūd (57), with his chain of narration from the Messenger of Allah (may Allah bless him and grant him peace), that he commanded a woman to mix salt with water, then wash the blood [from his saddlebag (ḥaqībah)] (58) with it. Salt is food, so things similar to it fall under its meaning. And Allah knows best.
Book of Marital Relations and Khulʿ (Divorce at the Wife's Request)
(56) Maʿālim al-Sunan 1/96. (57) Its verification was provided previously in: 1/81. (58) In (B) and (M): "from a menstrual cycle (ḥayḍah)". He means here the saddlebag of his mount that was struck by the blood.
