I was given a load of waste wool a few years ago and made a thread on using it:
uses for dag end fleeces. I actually had a lot of fun cleaning and spinning some of it, although it obviously had been rejected, much of it was OK for playing with after washing.
One thing I am going to try in my new polytunnel is using the fleece as membranes and wicking material in a wicking bed.
Unfortunately I can't use it generally as mulch as my dogs eat it and it makes them ill. I'm hopefully getting some more this week, but might use that in my dog resistant growing area, since it is relatively safe in there!