I have done this a few times. I put a large towel on my dining table. In a bowel I mix distilled water and a drop or 2 of dawn dish detergent. I use a vegetable brush and lightly scrub the board. I then use clear distilled water, go over the board with a half of a sham wow. I let the air dry it, then buff over it with a quilters mat smoother. The board is like new every time.