How to get rid of plastic and residual weird taste from food stored in tupperware? When I store leftovers in plastic tupperware and eat them later, I sometimes taste plastic. I do have some glass pyrex containers and they don't leave this aftertaste, but I would like to be able to use my plastic tupperware since I have so much of it.

Is there a special way to clean plastic tupperware? I tried handwashing and after it's dried, putting newspaper in there to absorb stuff.

On another note, it seems like some of my plastic tupperware absorb some food material onto itself. Kind of like forming a seasoning on a cast iron pan, except this is a waxy-food-weird-tasting film on the insides of the tupperware. Anyway to get rid of that? Soaping doesn't seem to work. This film is way too waxy.
There are many different types of plastic, but it sounds like your tupperware is made of the porous kind, which will hold on to food particles and explains your note.  Heat will expedite the leaching of chemicals into your food, so you should use the containers only for storage, and heat up and eat food from an actual plate or bowl.  If you have to continue using them, you could always wrap your food in paper to minimize contact.

Here's some more info