Is the continued presence of a cream on the hand considered an impediment to purifying the place of istinja, and does the presence of some of it adhering to the nails after washing the hands mean that they have not been purified?

It appears that the presence of the mentioned substance on the hand does not prevent the validity of istinja (definition) (cleansing after defecation or urination) and the purification of the area, if water is poured over both the hand and the area, the substance is removed from the palms of the fingers, and the area is cleansed, returning to its rough texture. It is sufficient to achieve certainty or a strong probability that the impurity has been removed. The cream remaining on the nails does not affect the validity of istinja because istinja is performed with the palms of the fingers and the hand, not with the nails. The remnants of the substance are not considered an impediment to the validity of istinja, especially if these remnants are under the nails. However, it is advisable to remove what is under the nails and purify them if the fingertips have directly touched impurity, due to the possibility of the impurity mixing with them. What is obligatory in istinja is a strong probability that the impurity has been removed, and smelling its odor on the hand does not cause harm.