Woolmark describes two relevant features of wool's odour behaviour: absorption of moisture vapour and the ability to hold some odour molecules within the fibre. These mechanisms help explain why wool clothing can develop a different smell profile from some comparison fabrics during use.

Wool Can Hold Odour Molecules Within the Fibre

The property is useful for socks, base layers and travel garments, but it does not make cleaning unnecessary or establish hygiene from smell alone. Soil, wear conditions and individual use still determine care needs. Washing releases captured material, so the fabric's odour performance belongs within a normal laundering routine.