Salam sheikh, I wanted to ask if one forgets to put water through the ear piercing, is ghusl still valid?
Ghusl isn’t valid if its an open piercing and water can get through it.
If you remember a little later, and you haven’t done anything that would normally break wudhu, then you can simply get water in the piercing and ghusl would be completed. The delay wouldn’t matter.
If you break wudhu, then ghusl has to repeated.