Just my two cents.....I think the type of soil, amount of soil and how long the soil may have been with the fleece can affect how much effort it takes to get it clean. When I lived on the other side of the Cascades, here in Oregon, the soil was sandy and, therefore, so was the mud. Here on the west side of the mountains our soil seems to have clay in it and so its "stickier". Over on the east side it averages about 10-20 inches of rain a year. Over here it averages 60-70+ inches annually and rains for about 7-9+ months of the year. I shear my sheep once a year. My sheep dont mind the rain and so will go out and graze in it. LOL, imagine how much water that could be hitting your back over the rainy season....its almost like the mud is washed IN the fleece by the time its time to shear. My goats are much more prissy, if its raining they only go out if they absolutely must(like mom is outside with treats or its started raining and they are working their way back to the barn) so they dont end up as weather beaten. The soil/mud on this side of the mountains is MUCH more difficult to get out of the fleeces. It can be done, most of the time, but it can take a lot of effort. I use my top-load washing machine, like I mentioned a few pages back, and I skirt some of my fleeces real heavily because of VM, mud or a combination of both. If I have a dirty fleece I really want to have the most I can get from, I usually end up opening a lot/all of the locks by hand or with a flicker/dog brush. I am fortunate in a way, since the animals live here, I will have a fleece again in six months for my goats and 12 for my sheep. So unless it is a really impressive fleece, has some special significance(like I sold or lost the animal), or I need a lot of fiber for a specific project, the skirting heavily on the really dirty ones is an ok thing. If I was buying the fleece and it was the only one that I had, it would be different and a lot more work intensive.
Oh, and the type of fleece seems to make a difference, the less crimp the easier and the medium lengthed fleeces seem easier than the short or long stapled ones, IMO.
Oh, and the type of fleece seems to make a difference, the less crimp the easier and the medium lengthed fleeces seem easier than the short or long stapled ones, IMO.