First of all, you will need to gather together all the materials you will need to felt soap with wool. You will need a bar of soap, wool, a towel and a dish of hot water. An optional item to use is a felting board or washboard.
Now, you will want to start by wrapping the wool around the bar of soap. Be sure to wrap the wool around it so all the surfaces of the soap are covered. If you want to be creative, you can add additional colors of wool for a pretty decoration.
Dribbling hot water on the soap is the best way to wet it. You don't want to drench it with water at this point, or the wool will more than likely slide off. Patting it will help you to know if the wool is wet all the way through.
Once you notice that the wool is pretty wet, you can begin squeezing it. You still need to dribble drops of water on it regularly. You will start to notice the wool making a woolly outer layer around the bar of soap. Continue to squeeze it, moving it around in your hands while you do so. Make sure you add water every so often to keep your hands slippery.
You should notice it starting to felt and losing the wrinkles now. You should notice that the wool isn't slipping off when you rub your hands over the surface. You are probably seeing a lot of soapsuds too!
If you have a washboard, now is a good time to start rubbing the felted soap on it. If you don't have a washboard, you can just continue to rub it and throttle it in your hands. Make sure to rub it all over, and in circular motions. Don't forget to rub the sides. A good way to felt the sides is by turning it in your hands. You should really be seeing the felted soap lathering up now.
Dip it in the dish of water to see if it has felted down to make a snug, tight cover around the bar of soap. If it seems a little fuzzy rub it some more. When you notice that it is beginning to get snug around the bar of soap, you should run it under cold water. This will tighten up the wool and rinse off the suds. You will want to gently squeeze out the extra water. A few suds will probably leak out. Don't worry about them. Pat it dry with a towel. You now have your own bar of felted soap!