The purpose of cleaning your dream catcher is to empty it of the dream spirits living there. You must preform it every six months.
1.take down dream catcher
2. Weave yarn or string through the dream catcher until you have a square spiral.
3. Open door and/or window(so spirits can escape)
4. Think:over the course of the last emptying, this spirit trap has been engulfed with unwanted spirits. By my powers, these spirits are free.
5.pull out yarn/string, and wait thirty seconds before closing your door/window.
6. Leave a tiny chest/drawer open for a spirit to live in overnight.

It is very important to release this spirit the next emptying or else it will curse you or cast a spell on you.