like if i put leftovers away, and they stay there for a long time when i go to wash them it still smells like the food that was in it, i even tried soaking it in hot soapy water first then actually washing it, but its still smelly, (and sorry if i spelt tupperwear wrong) lol
Miss Colleen's answer of baking soda is a good one, but if it's really bad and that doesn't work, you might try a solution of household bleach and water. don't use full strength bleach because it will make the tupperware more pourous creating a worse problem next time.
Trying scribing it all in Hot water with Bleach.
Burn it and use metal tins...lol
Scrub it with baking soda.