Gently scrub your board with a sponge and hot, soapy water (we recommend using a mild unscented dish soap, such as Seventh Generation Free & Clear Dish Liquid ... of chlorine bleach and water ...
This may seem obvious, but plenty of people load dishwashers with upside-down bowls and sideways cups ... with bleach (including non-chlorine bleaches, like oxygen bleach) in a liquid form ...