Sometimes it is the best to approach the issue other than let it simmer. We had 2 employees that had a problem, one was unaware and did the best to fix it, the other I had told a couple of times but, this particular employee also had other diabilities.
It IS hard when it is of such a particularly personal matter, but like you said, he was unaware...bit like going to a hospital, we all notice going in but after the first few hours you dont smell it anymore, imagine living with it...you'd be immuned!