I wore my hat on a bad hair day (to hide the fact that I hadn't washed my hair ) and now it niffs and makes my hair niff even when my hair is squeaky clean.
The outside is wool and some sort of treated cotton (feels vaguely oiled), and the lining is fleece. In between is a waterproof membrane. The care label states that the hat cannot be cleaned by any means.
Any ideas how I can clean the inside?