All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Some scholars held that a small amount of dirt that is hard to remove is excused. This opinion was chosen by Ibn Taymiyyah . It is stated in Ar-Rawdh Al-Murbi' (a Hanbali book of Fiqh) with its commentary that: “A small amount of dirt under the fingernail is harmless, and (so is) what is similar to that such as something inside the nose that prevents the water from reaching the skin. Ghusl is valid in this case; and this is the view chosen by "Al-Muwaffaq" (Ibn Qudaamah) and others, and this is considered the correct and preponderant opinion by Al-Mardaawi, the author of Al-Insaaf. The Shaykh (Ibn Taymiyyah) said: ‘A small amount of dirt in any part of the body and what is inside the cracks of the feet is excused, and the same ruling applies to any small amount of a thing clinging to the body that prevents water from reaching the skin, like blood, dough or the like.’ This is the view chosen by him (Ibn Taymiyyah).” [End of quote]
A well-established Fiqh principle is that “Difficulty brings about ease and the more constricted a matter becomes, the wider it should be.” This rule is implied in the verse that reads (what means): {He has chosen you and has not placed upon you in the religion any difficulty.} [Quran 22:78]
Finally, we would like to warn the dear questioner from following the devilish whisperings in this regard. His previous questions indicate that he suffers from satanic whisperings concerning disbelief and polytheism and another question indicates that he suffers satanic whisperings in relation to Ghusl. We believe that this question is a continuation of following such satanic whisperings. If he does not start ignoring such whisperings totally, they may lead him to leaving the religious obligations. So, dear Brother, fear Allaah and pay absolutely no attention to such whisperings.
Allaah Knows best.