Baking soda and sunlight beat any fancy cleaner.

Baking soda is the cheapest fix for lunch box odors, but you need to let it sit.

First, wash the whole box with warm soapy water. Most lingering smells are trapped in grease or seams, and soap actually gets that off. Rinse well and dry it completely — a damp lunch box will get musty fast.

Then the actual deodorizing: sprinkle a thin layer of baking soda inside, close the lid, and leave it overnight. No need to scrub it in. Just let it sit. In the morning, dump it out and wipe it down.

Sunlight works too. If it’s a sunny day, leave the empty box open in direct sun for an hour or two. UV light kills odor-causing bacteria, and fresh air does a lot of the work.

For rubber seals or gaskets, pop those out and soak them in a bowl of white vinegar and water for ten minutes. That’s usually where tuna and onion smells hide. Wiping the inside down with vinegar after washing also helps neutralize smells without leaving a weird perfume behind.

Avoid bleach-heavy sprays and lemon-scented cleaners for this. They leave their own smell, and nobody wants a lunch box that tastes like citrus air freshener.

Your future tuna sandwich will thank you.