Try sprinkling baking soda in the containers and the pour hot water in them. Put the lid on and swirl the mixture around. Take a rag with vinegar on it and wipe down the container.
Every time I clean my mirrors, they end up having tons of streaks and almost look worse than before I started. What could I use to clean them that won't leave streaks...
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Those are probably from meat or oily sauces with tomato-based products in them.
The oil has permeated the oil of the Tupperware’s plastic, by heat.
Real Tupperware has a lifetime warranty and I would try to get it replaced, as it won’t ever come fully clean, in my experience.
I would try a paste of Dawn & Comet.
Try sprinkling baking soda in the containers and the pour hot water in them. Put the lid on and swirl the mixture around. Take a rag with vinegar on it and wipe down the container.