How do you get tomato sauce stains out of plastic tupperware?

[GYo]

Hello

Friend gave me tub of left over sauce after a meal in one of her tupperware pots. We transfered it to one of our pots but it's badly stained her nice pot.

Is there a way of getting it out? Dont want to give it back stained really

TIA

Do you have any sterilising tablets ? When we get orange tupperware, I just soak it in a double strength solution of Milton tabs, and all the stain comes out

ooh thanks CMOT, i have some milton, will try that!

Leave them out in the sun.

Milton or lemon juice