There used to be a shop in Kendal where you could buy wool from any breed for spinning into wool.
My wife Francie is a spinner, and made me a sweater of Herdwick wool- but unlike other lovely sweaters she's made from Jacob & Welsh Black wool, it wasn't a success- if you can imagine a jumper made from Brillo pads, you wouldn't be far off...
she tried to spin some cotton grass one day, but that didn't work either!