Put stained plastic in the sun. Seriously.

The fastest way to get a tomato stain out of a clear plastic lunch box is to leave it in direct sunlight, wet, for a few hours.

That stain is lycopene, the pigment that makes tomatoes red. It’s oil-soluble, which is why dish soap and scrubbing barely touch it — it has soaked into the plastic’s pores, not just sat on the surface. UV light breaks the pigment down, and plastic is one of the few materials where this trick works like magic.

Here’s the method: rinse the box, leave a thin film of water inside (or just wet the outside if the stain is on the lid), and set it in a sunny windowsill or outside. Rotate it every hour or so. Most stains are gone in a few hours; heavy ones might take a full day.

If it’s cloudy or you’re impatient, a baking soda paste works okay, and a diluted bleach soak does help — but bleach can cloud or weaken plastic over time, and it won’t reach what’s already soaked in. Also, if the plastic is scratched or old, the stain might just be permanent. Scratches give the pigment deeper places to hide that UV can’t reach.

Sunlight is free, and it beats scrubbing until your arm falls off.