4 Ways to Remove Stains From a Cooler
Use a baking soda paste for most stains Mix baking soda and water in a 3:1 ratio. Scrub with a soft sponge, letting it sit for 15 minutes on set-in stains, then rinse thoroughly.
Try hydrogen peroxide for stubborn tomato stains Spray it on, let it fizz for a few minutes, then scrub. Sunlight also works as a natural bleach, so leave the cooler open in direct sun for a few hours.
Avoid bleach unless sanitizing Bleach is overkill and leaves a smell that plastic holds onto. If you use it, rinse multiple times.
Accept faint shadows Coolers are for ice, not interior design. A faint remaining stain is not worth stressing over.