Assalaamu alaykum. I know that if a person remembers not having washed a part of their body during Ghusl (ritual shower), they can wash it when they remember. That said, if a person remembers but does not wash the missed area immediately, is their Ghusl invalidated? For example: they are walking towards the washroom in order to wash the missed area and someone stops to greet them. If they pause to shake hands and greet each other for a moment, does that invalidate the Ghusl? Furthermore, what if that area was already washed properly but they did not perceived, and the above situation occured while rushing to wash the "missed" area. Would the Ghusl be valid given that the area had actually been washed? May Allaah reward you.

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

It is clear that you are affected with Waswasah (obsessive whispers); so we warn you against it, and we advise you to get rid of it and not get carried away with it, as getting carried away with Waswasah leads to a great evil.

If a person has doubts about an act of worship after having finished it, then he should not take this doubt into consideration. If he doubts having washed a part of his body that must be washed in Ghusl, then his Ghusl is valid and he should not pay any attention to this doubt.

However, if he is certain that he did not wash this body part, then successive washing is not a condition in Ghusl according to the view of the majority of the scholars. Therefore, he is not obliged to wash it immediately, but whenever he washes it, it is sufficient and his Ghusl is valid.

In the light of the above, you should know that the Ghusl in the cases you asked about is valid.

Allah knows best.