Seriously, dude. There's no reason it should smell the way it does. It's not an asshole. It doesn't even perform any specific function except just chilling there. You forget you even have a belly button until every so often you look down while showering and clean it out with your washcloth then smell the washcloth and then think "Damn, I should have used toilet paper for this. I don't wipe my ass with a washcloth and it smells almost exactly the same."