Bleach is a good cleaning agent to purify your cutting board. Take 1 teaspoon of bleach diluted in 2 quarts (2 liters) of water. Dip a brush into this solution and then scrub with the brush in small circles. Don’t saturate the wood; remember that a little bit will go a long way. Once you finish scrubbing, wipe the board with a slightly damp paper towel, and then immediately dry it with a clean cloth.