<---Yup! Hair conditioner. Here's how:
1. If the hat needs to be washed, wash it gently in tepid (room temperature) water, then rinse, in the same temperature water, until all the soap suds are gone. If the hat does not need to be washed, then simply soak the hat in tepid water until it is completely wet.
2. Gently press all the water out. Make up a new basin of water of the same temperature, and into that basin, dissolve a tablespoon or two of hair conditioner.
3. Swish the wet hat through the solution, then let it sit for about 5-10 minutes. Again gently press out the water. Do not rinse out the conditioner.
4. BE CAREFUL not to agitate the hat or felting will result. Swish, swish, swish--that's all you need to do.
5. Roll the item in a heavy towel, step on the towel/hat jelly-roll to press out all the water,unroll, then lay the hat on another, dry, towel. Pat into shape and let dry.
Some hair conditioner leaves a sticky trace, some does not--if it leaves your hair feeling sticky, it'll probably leave your hat feeling sticky, so use a different kind. Conditioner that leaves your hair soft and smooth will do the same for your woolens. Also, the kind of hair conditioner to use for this trick is the ordinary supermarket kind for "normal hair." Specialty hair conditioners (volumizers, curl releasers, chemical damage-repair conditioners and the like) may have odd interactions with wool. If in doubt, try your conditioner on a swatch, first.
If you try this trick and it does not sufficiently "de-itchify" your hat for you, then click the links at the top of the column for information about lining knitting with polar fleece.
* Of course, this trick works for all woolen garments, not just hats. Scarves and mufflers--in contact with delicate neck skin--generally benefit from conditioner's softening properties, and this works for itchy sweaters, too.
--TECHknitter
(You have been reading TECHknitting on: softening itchy wool with hair conditioner.)