What is the ruling on Ghusl and Wudu if one forgets to remove accumulated oils and dead skin from the the nose and ears with soap?

Skin oils do not prevent ablution (wudu) or ritual bath (ghusl), and there is no need to remove them. As for skin flakes that are still attached, it is sufficient to allow water to reach them. If they are detached, then what is beneath them must be washed. Beware of obsessive doubts (waswasah).