Baking soda paste, then sunlight.

For stubborn lunch box smells, start with a baking soda paste and let it sit overnight.

Plastic is porous, so curry, tomato sauce, and fish oils seep into the surface. Vinegar just masks the smell temporarily. A thick paste of baking soda and water — enough to coat the inside — actually pulls odors out while you sleep. Scrub it around, leave it, rinse in the morning.

If it still lingers, put the box in direct sunlight for a few hours. UV light breaks down the odor molecules that scrubbing can’t reach. That combination fixes 90% of lunch box stink.

If it still smells after that, just throw it away. Some plastic is too far gone, and no amount of soaking in lemon or bleach will fully save it. A new container costs a few bucks. Your sandwich doesn’t need to taste like last week’s leftover pasta.

Future you deserves a lunch that doesn’t smell like regret.