Is reciting Surat al-Ikhlas 10,000 times a means of freeing the deceased from hellfire, or is that an innovation (bid'ah)?

What you were told, that reciting Surat Al-Ikhlas 10,000 times frees the deceased from the Hellfire, has no basis in Islamic law. We do not know of anything clear regarding reciting Surat Al-Ikhlas for the dead, nor from the righteous predecessors. The reported hadith, "Whoever recites 'Qul Huwa Allahu Ahad' (Say: He is Allah, the One) a thousand times, has bought himself from Allah," is a fabricated and weak hadith. It is important to note that many of the hadiths reported concerning the virtues of certain surahs or verses are weak or fabricated, and they must be presented to scholars of hadith to distinguish the authentic from the weak.