That isn't the question. It's how does earwax stop water from staying in your ear. I suspect it's the opposite. If you have almost no earwax and your ear canal

That isn't the question. It's how does earwax stop water from staying in your ear. I suspect it's the opposite. If you have almost no earwax and your ear canal is fully open, water can drain out. But if the canal is say 80% smaller at one point due to wac buildup, then perhaps water can be forced in from pressure and be difficult to drain.