Is it obligatory to get water into the earlobe piercing designated for an earring when performing ghusl, knowing its difficulty?

It is obligatory to get water into the open earlobe piercing during ghusl (definition). There is no need to insert a stick or similar object as long as water flows over it. If the piercing closes after the earring is removed, and it reaches a state where water would enter it if it passes over it, then it is obligatory to let water pass over it, without undertaking any extra effort beyond letting it pass. However, if it has a depth within the flesh, it is only obligatory to wash what is visible of it.