Like most anything else dealing with fiber arts, prep goes a long way when scouring a fleece.
I'll spend a few hours picking over a fleece, shaking out VM, discarding wool with burrs or poop. I skirt it viciously, removing leg, belly, neck & britchen wool. It all goes into the compost pile or directly in the garden for mulch.
Then I make sure all the 2nd cuts are picked out, then will separate the rest of the fleece by color, or staple length or fineness.
Next, I open the tips of each and every lock.
Yup, a lot of prep before the fleece hits the washer, but it sure saves time, water and detergent because I can generally get a fleece clean with one wash and one rinse with vinegar. It also saves time in prepping the fiber for spinning, since it is already picked and VM removed. If I didn't feel like carding or combing the locks, I can spin right after the fleece dries!