...instead of washing them every time.
Wool has a natural resistance to the growth of micro-organisms and odors, so you can use wool garments for several days without having issues with smell. The reason for this is a combination of two things: wool fibers absorb moisture and they have a negatively charged, scaly surface. Bacteria, which lead to bad smells, thrive best on smooth, positively charged surfaces – such as those synthetic fibers have. Therefore, you may not need to wash wool in the machine after use. Instead, try hanging int outside in the open air and let it clean itself. This saves both the environment (no machine washing!), and preserves the quality of the wool for longer.