I would like to know what is the basis of the claims that prophet' hair has blessing or his other body parts such as nails etc. Can blessings come from such things? Is there any hadith that supports or are these just whims and fantasies of maulvis?
There are some Ahadith saying that some people were keen to use the left over of the water that the Prophet (sws) would use for ablution or liked to get hold of his hair, etc. However the Prophet (sws) himself never encouraged such an act and there is nothing in the Qur'an to inform people about any blessings as such.
We can conclude therefore that the above practices were only natural reactions of people who loved the Prophet (sws) and appreciated the presence of a person (or his belongings) among them who was chosen by God as His messenger. If one ascribe any religious significance to this and consider it as part of the teachings of Islam then it will become Bid'ah (innovation).