Soak first, then go in with a bottle brush

Soak the whole lunch box in hot soapy water for 10 to 15 minutes before you try to scrub those tight corners.

That’s the whole trick. Crumbs in dividers or attached cups are usually stuck because they’re dried on, and a soak loosens everything so the hard part becomes just rinsing them out.

For what’s still left, use a long-handled bottle brush or a pipe cleaner to reach into crevices. An old toothbrush works for the wider slots. And if something’s really wedged in, a toothpick or bamboo skewer will dig it out without scratching the plastic.

One last thing: after washing, turn it upside down on a dish rack so water drains out of those little cups. Sitting water in a hidden corner is how you get that funky smell. Future snacks will thank you.