Ingredients to make felted wool : lubrication (soap, detergent, natural grease in the wool) ; temperature shock (esp hot to cold) ; agitation
So, to wash the rug without felting it :
1. Overnight soak in water at room temperature, no soap.
2. Remove gently and without wringing. (You will be amazed how much $*!£ came out!!)
3. Prepare two containers of water at the same temperature - very hot, too hot for your hands. To one, add quite a bit of washing up liquid. Do not froth it up.
4. Place the rug softly on top of the container containing the water-and-detergent. Let it sink by itself. If it is still floating after a few minutes, press it down very gently and steadily; try to avoid making suds.
5. Leave the rug in the water for 10-15 minutes. No need to agitate or anything.
6. Gently, and again, without making froth, remove the rug from the water and place it gently on top of the water in the second container. Again let it sink in, help it gently if if needs it, leave for 10 mins, then remove.
7. Keep rinsing until no more soap in rinse water. Each time, make the water it is going into the same temperature as the water it came out of, or slightly hotter.
Once there is little soap in the rinse water, you can gently press the water out of the rug before its next rinse. Do not wring; fold and press.
After the last rinse, you can press harder to get it a bit drier, then place it between two towels, roll it up into a sausage, put another towel down and walk all over the sausage! Then put it somewhere flat to dry.