The property that keeps wool smelling is the one that helps regulate temperature. The breathability of the fibers means that much of the moisture absorbed by the material is converted into steam and released into the air.
Wool comes from animals that live in variable temperature climates, which is why they can regulate the user's temperature well.
Wool items are easy to clean because the outer surface of the wool fibers consists of a series of overlapping scales (similar to feathers on a bird), which means that dirt sits on the surface of the fiber and therefore allows for easy removal. Airing or washing as needed is enough.
