wool is a magical thing...I believe its fibers make you "fuzzy" shaped to critters...not starkly outlined...I believe its more muted than cottons or manmade materials in the way it appears, reflects sunlight, etc, and that is also helpful.
all wool, as Orion said, can be gentle cycle washed in cold water and woolite, and blocked to dry.
Dry cleaners use a chemical called PERK that is a carcinogen and does have an odor. Even if you cannot smell it (when they do it right at the dry cleaners) deer and other critters will pick it up..and if the DC does it wrong its even easy for you to smell it.
I wash my stuff once a year after season and block it up on towels and then outside to dry and it doesnt shrink.