Question: The Prophet (ﷺ) said:
إذا توضأ أحدكم فليجعل في أنفه ماءً
If anyone of you makes wudu, then let him put water in his nose [Saheeh Muslim no. 237]
Some people have allergies in their noses or other than it and are not capable of snuffing water into the nose. So what does [such a person] do?
Answer: “It is not necessary to snuff water. That is: if he takes water in his hand until he enters it to the nostrils, that suffices. The water reaching the top of the nose is not an obligation and I do not think, inshallah, that there is any harm in it”
[Liqaa al-Bab al-Maftooh no. 215]
Faisal bin Abdul Qaadir bin Hassan