What is the correct idiom for on tip of his nostril?

The idiom you're likely thinking of is "on the tip of one's tongue".

It means that someone is very close to remembering something but can't quite recall it.

For example:

* "I know his name, but it's on the tip of my tongue."

There is no idiom related to "on the tip of one's nostril."

Psycholinguistics

ZG·Lingua