My kids lunch boxes are always a worry with the smells that radiate from them. Well here is a simple way to keep them fresh. Soak a piece of bread in vinegar and let it sit in the lunchbox over night. All the odors will have gone.
You can leave lunch boxes odor free when you scrub them with an sos pad to get off all the dirt, then wipe them out with a mixture of baking soda and water. Making a thick paste, the baking soda is going to absorb all the odors left behind in the lunch box. The sos will not scratch the plastic and it will leave your lunch box looking white - as new!