People ask me this a lot. They've heard wool is itchy (that's a different conversation) and they assume something that holds moisture must hold smell too. It doesn't. In fact, it does the opposite.
Here's what's actually happening: wool contains lanolin, a naturally occurring wax that coats each fiber at a molecular level. When urine, or sweat, or whatever the day throws at you, meets lanolin, it triggers a mild chemical reaction. The lanolin essentially converts it. Neutralizes the ammonia. Breaks it down into something inert. Soap and water, basically.
So wool doesn't just block smell. It dismantles it.
This is why you can wear a Bumby cover for days, air it out overnight, and it's genuinely good to go. This is why your wool sweater doesn't smell like a gym bag after a long hike. The fiber is doing chemistry you never asked it to do, constantly, quietly, without fuss.
There's a reason humans have been working with wool for thousands of years. It works. It still works.
"Does it really not smell?" Yes. Really.