Sheikh `Abd al-Rahmân b. Ibrâhîm al-`Uthmân, professor at al-Imâm University
It is true that some Muslim jurists have expressed the opinion that burying hair and fingernails is a preferred practice.
For instance, al-Nawawî, the eminent jurist of the Shâfi`î school of law, writes in al-Majmû`: "It is preferred to bury what is trimmed or cut from a person's hair and nail. They should be buried in the ground."
Likewise, Ibn Qudâmah, the leading Hanbalî jurist, writes in al-Mughnî: "It is preferable to bury one's fingernail clippings and the hair left over after the hair is cut."
There are some hadîth narrated to that effect, but none of those hadîth are authentic. Among them is where Mayl bint Mashrah said: "I saw my father clip his fingernails and then bury them. He said: 'My little daughter, I saw Allah's Messenger (peace be upon him) doing like this." [Mu`jam al-Tabarânî al-Kabîr]
Then there is the narration from Wâil that the Prophet (peace be upon him) used to tell people to bury hair and fingernail clippings. [Shu`ab al-Imân]
It is related from Ibn `Umar that Allah's Messenger (peace be upon him) said: "Bury fingernails, hair, and blood, since it is dead." [al-Kâmil by Ibn `Adiyy]
Ahmad b. Hanbal was once asked if he had anything about buying hair and fingernail clippings. He said: "Ibn `Umar used to do so." However, Ahmad did not mention any chain of transmission for this statement.
To say something is preferable in an religious context is to assert an Islamic legal ruling for it. Such a ruling can only be established by evidence. Since none of the hadîth that indicate this matter are valid as evidence, a person may discard of fingernail and hair clippings in any way that he finds convenient, by throwing them in the garbage or buying them, or what have you.
And Allah knows best.
Source: Islam Today