Put on gloves and a mask for your own safety and remove anything that is stored in the crawl space before you begin. Make sure these items don't also have mold on them. If they do, they will also need to be cleaned.
Mix laundry detergent and hot water in the bucket. Keep a rough cleaning pad wet with the mixture, and use it to scrub the walls inside of the crawl space. Once the mold has been removed, scrub the same walls again with just hot water.
Rinse out the dirty bucket. Then mix water and bleach in it. You don't need more than 1/2 cup of bleach for a gallon of water. Use the rough cleaning pad to clean the walls inside of the crawl space with this mixture.
Let the crawl space walls dry on their own. Once they are dried completely, you can return items back into the crawl space.