Wash wool or other fibers for spinning.

Step 2 Into the bath

Pour in maybe a quarter cup of detergent at most. You want it strong enough to work but not sudsy. That's just a hassle because you can't run water on the fleece itself. No agitation! It'll felt. That means it's a lot harder to rinse out suds. 

Fill the bucket most of the way full with hot water. Very hot in this case should be a bit too hot to put your hands in. I used water from our instant hot tap that's set at about 190F. Not sure what the minimum would be but that works well for me. 

Now take your fleece and gently set it on top of the water. It should sink quite a bit on it's own. Let it do that and slowly add more until there are only a few inches of water at the top. You want to give the grease somewhere to go and be able to tip the water off with the grease floating on it so that it doesn't settle back into the fiber. 

You can gently push the fiber down with a clean stick or wooden spoon to get it the rest of the way under. Do not stir or agitate the fiber. You will be tempted to do it but don't! While hot water aids in the shrinking and matting it is actually agitation that binds the fibers. Let it soak!  

Fifteen minutes is probably sufficient. Another important thing is to not let the water cool too much. At this stage you are in to to the end. If you stop the grease will be more evenly distributed and have soaked into the fiber even worse if it is allowed to cool. 

Now would be a good time to go heat more water if you need to.