Unless you must, it is recommended that you do not rinse or water mushrooms, because they are extremely porous. Simply brush them using your brush or mushroom varnish. Gently brush your mushroom away to get rid of any mud. If you must rinse the mushrooms, place them in running water.
Dry it off by squeezing out some of the water. Slice or tear mushrooms into pieces, and their texture is similar to a cauliflower. Place onto a towel and let it dry out before baking.