Empty the contents of your lunch box. Turn it upside down and shake it a little to remove all dust and dirt. Add a small amount of mild liquid soap to warm water. Dip a clean cloth into this mixture, wring it out thoroughly, and wipe down your lunch box. The liquid soap will also disinfect your lunch bag while cleaning it. To prevent the lunch bag from absorbing too much water, the cloth should not be too wet, and the wiping process should not be prolonged. Before starting the cleaning process, test the cleaning product on a small area of the lunch bag to ensure that it does not damage the material or color. Dry the Lunch Box by Wiping It Down Wipe the bag with a clean, dry cloth to remove any remaining water and soap. Then, let the lunch box air dry. Avoid using a dryer during this step, as it may cause the bag to shrink. Lunch Boxes