How to clean inside of a steel thermos flask?

Question

scales are formed , not able to remove it with bottel brush

Answer 1

Use white vinegar with hot water, and a bottle brush to get to the bottom of the thermos.
Please, don't use bleach!!! it's a dangerous product to use near food.

Answer 2

Start with a solution of soapy water and slosh the mixture inside the vessel. Rinse clean, (may take several rinses to get all the soap out) then mix a solution for water and vinegar 50/50 and fill and let stand for a few minutes.
Rinse three times with clean water and let stand until dry.
You should be ready to go.

Answer 3

try a bottle brush with a 1/4 teaspoon of bleach and hot water , rinse well and air dry upside down to drain all the water out .

Answer 4

Use a denture cleaning tablet, like Polident. Pure vinegar soak will remove scale if the Polident doesn't.

Answer 5

Bottle brush with a paste made form vinger n bicarb, rince well.

Answer 6

A bottle brush!

Answer 7

I use about tablespoon of baking soda, then fill with water and soak overnight.
or
Fill with water and drop in an efferdent tablet.

Answer 8

i'd buy some of those sterilising tablets used for sterilising babies bottles, i had some some really dirty cups and you soak it for a couple if hours and they fizz away and when you rinse it out it should be as bright as a button.

Answer 9

use warm water and baking soda, leave it overnight wash it using bottle brush.

Answer 10

vinegar and warm water