The Messenger of Allah ﷺ said, "Blow your nose thoroughly two or three times."
قال رسول الله ﷺ: استنثروا مرتين بالغتين أو ثلاثا.
Abu Dawud (141) and Ibn Majah (408) both narrated it through the route of Waki, from Ibn Abu Dhib, from Qariz bin Shayba, from Abu Ghatfan Muri, from Ibn Abbas, and he related the hadith. Its chain is hasan because of Qariz bin Shayba, for there is no harm in him. Ibn Saad said, "He narrated little hadith." Nasai said, "There is no harm in him." Ibn Hibban mentioned him among the trustworthy narrators (5/327). Someone like him has his hadith graded hasan, and this is one such case. See the rest of the hadiths about rinsing the mouth in the chapter on the description of the Prophet's ablution ﷺ.