Sunlight fixes smelly plastic. Baking soda helps too.

Baking soda and a few hours in direct sunlight will get almost any garlic or onion smell out of a plastic lunch box.

The problem isn’t that your lunch box is dirty. Garlic and onion release sulfur compounds that seep into microscopic pores in the plastic, and soap and water just can’t reach them. So stop washing it three times and expecting different results.

Do this instead: make a thick paste of baking soda and water, rub it all over the inside, and let it sit for 15 minutes. Rinse it off. If the smell is still there, give it a soak in white vinegar for half an hour. Then wash it normally.

The real fix is sunlight. Set the clean, open box outside in direct sun for a few hours. UV rays break down the odor molecules in a way no chemical cleaner can match. Overcast day? A UV lamp or even a strong windowsill works, just slower.

If you need it fast, cramming crumpled newspaper inside overnight absorbs a lot of the smell too, but sun is the cure.

Your lunchbox will smell like lunch again, not last week’s lunch.