How do you clean oxidation from the inside of a thermo pot /water boiler.?

Question:This thing holds about a gallon of water . It boils with a press of the button and stays warm/hot. You can press to release the water for drinking tea/coffee or whatever you want hot water for.

Answers:
Pour about a cup of white vinegar into it and let soak over night then flush it out in the morning ( you might want to add food coloring to be able to discern when the fluid in it runs clear). Good luck and be COOL!!!