The Messenger of Allah ﷺ said, "Rinse your mouths after drinking milk, for it has fat in it."
حدثنا أبو مصعب حدثنا
أن رسول الله ﷺ قال مضمضوا من اللبن فإن له دسما
[hasan] Tabarani reported it in al-Kabir, 6/125, no. 5721, from the hadith of Abu Musab and others, with this wording. Busiri said, "This is a daif isnad. Abdul-Muhaymin, of whom Bukhari said, 'His hadith is munkar.' The preceding hadith serves as a corroborating witness for it."