You can use direct shower water, shake dry, and then take a hair dryer to cool the air for a while.
Or take a cotton swab and rub it in, not too much water pressure, and when you're done, it's as good as new. This is how I cleaned it so far it's working
Not afraid of trouble can use a long brush, elastic, and long enough, you can wipe all over the heating gap, water can also ensure that dust does not fly.
No, this cooling back clip does not support waterproof, can not be washed