Seeking barakah from this hair is not permissible and it is a means that may lead to shirk, because it is impossible to prove that it is actually a hair of the Prophet (blessings and peace of Allah be upon him). By the same token, it is not permissible to build a mosque for it and keep it in that mosque, even if we assume for argument’s sake that it is actually a hair of the Prophet (blessings and peace of Allah be upon him) and is proven by an unbroken, sound chain of narration.

Prophet Muhammad explained in the Hadith about intercession that no one will be brought out of Hell except those who died believing in Tawhid and uttered the Shahadah and had in their hearts something of faith.