I guess Muhammad never heard of Naegleria fowleri.
Many people perform ritual nasal rinsing. This practice is included in Yogic, Ayurvedic, and Islamic traditions. Within the Islamic faith, ritual nasal rinsing is included in a cleansing process called "wudu" or "ablution." It is usually performed several times a day in preparation for prayer.
https://www.cdc.gov/parasites/naegleria/ritual-ablution.html
Notice the Jewish religion, wisely, has no such ritual.