The sun will fix that tomato stain

Sunlight is the best tomato-stain remover for plastic lunch boxes.

It sounds like a trick, but it works because of chemistry you don’t need to fully understand. Tomato sauce stains come from a pigment called lycopene, and UV light breaks it down. So wet the container, set it in direct sun for a few hours, and the red fades — often completely. I’ve done this with cheap plastic Tupperware that looked ruined, and it came out looking new.

If it’s sunny where you live, that’s the whole answer. Just be patient; it takes a couple of hours. Flip the container halfway if the stain is on a side.

No sun? Make a paste of baking soda and water and scrub gently with a soft sponge. Or soak in an oxygen bleach solution (the stuff with “Oxi” in the name) for an hour. Skip the heavy scrubbing with steel wool — scratches give stains a place to hide permanently.

Dish soap alone won’t touch a set-in tomato stain, so don’t waste a sink full of water on it. Sunlight costs nothing and never fails.