There is no reason that someone needs to trim his nose hair; the function of nose hair is to prevent dirt and pathogens from entering the nasal cavity. If the hair causes someone to feel self-conscious, it is appropriate to trim the hair so that it is less conspicuous.
The objective of nose hair removal is to reduce it to a suitable amount. Some hair needs to be left in place so that it may perform its biological function.
A trimmer specifically marked for nose hair removal is the safest way to trim nostril hair. The trimmer is inserted gently into the nostril so that it may clip the hairs to a desired length.