I have a wool blanket over my mattress protector but below my bottom sheet of my bed. I hung it on the line after about a year of use and I'm absolutely disgusted by the hair and dust that has come off it. I've been shaking it here and there and lots of dust falls of it. I'm going to leave it for a few more hours in the hope the wind and sun help clean it a bit. Any tips on it? Should I wash it in the machine?