Kids love to do real work, especially by your side.
Have your rags, cleaning cloths, spray, and dish soap nearby.
Work together to pull all the food out of the fridge. Teach them how to tell if food looks spoiled, and get them to remember what day those various leftovers are from.
They can spray and wipe the empty fridge, but what they really love is standing on a stool at a sink full of warm, soapy water, cleaning the fridge drawers and shelves.
Ask slightly older children to figure out an organizing system to get the food back in. You might actually like what they come up with. And next time you make dinner, they’ll be happy to gather all the materials for you.
You can do a similar process with a junk drawer (have the garbage can, a bag for “goes in another room,” and a bag for donations). Kids know when they’ve done real work, and they feel proud of themselves, which translates into good moods and potential future volunteer helpers.