I dread having to toss out my Tupperware. I was going toss one container that had been used in the microwave un-teen times to the point I decided it was time to toss it. I hesitated though. I took a steel wool pad and started scrubbing in a circular motion on the inside and began to see results. It became smooth and clear again. So if you're like me and have been hanging on to Tupperware you thought should be trashed, try out this method before you do.
Well, I feel the same way about my plastic/microwaveable containers. However, I refrain from saving them especially after they have been used for a long time because the plastic might have corroded somehow. I think that there will be health side effects if I will continue using them. Instead, I just use them as planters for my indoor herbs and other plants.