Spinners will wash their own. All they want from you is that the mucky daggy bits have been removed, and the fleece hasn't been messed about with too much.
To test a lock for strength, choose a lock from the middle of the fleece, not near the edge. Hold it in two hands, next to your ear, and give it a good hard snap. You'll hear a 'ping' if it's sound, and a kind of crackle, like a crisp packet, if it's broken.
The cobwebby nature of the fleece suggests they may be nice for spinning, as shown on that Woolsack page I linked to.
To contact spinners in your area, you can of course ask on here! Or there's Spinners in the UK Marketplace on Facebook. Or look up your local Guild on the map
hereBut if you really don't want to be bothered, just bundle them up as best you can and put them in the BWMB wool sheet. They'll pay you
something and they'll be out of your way.