How to Clean Backpacks and Lunchboxes Backpacks and lunch boxes CAN be cleaned – here’s how: Empty the backpack and/or lunch box completely – open all the pockets and compartments and make sure that there isn’t anything hiding. Check the tags to double check that your item can be laundered in the washing machine. If it can’t follow the directions at the bottom of the post. Place in your washing machine and wash on gentle with your favorite detergent. I use Clean Mama Laundry Detergent Spray – it