The inner flasks of thermoses are most often made of stainless steel, glass or plastic. The same tools are suitable for removing dirt from the surface of these materials.
It will help to get rid of tea and coffee plaque.
Pour baking soda into the flask and fill with hot water (you will need 5 tablespoons of soda for 500 ml of liquid). Close the thermos and shake it vigorously to mix the contents properly. Leave the mixture to act for 3-5 hours.
After that, shake the thermos again, pour out the soda solution. Add a couple of drops of dishwashing detergent and hot water to the flask and shake the container. Then rinse it under running water.
This tool will cope with pollution and at the same time eliminate unpleasant odors.
Pour citric acid into a thermos and add hot water at the rate of 1 tablespoon of crystals per 500 ml of liquid. Close the container and shake the ingredients thoroughly.
After 3 hours, shake the thermos again, pour out the contents. Thoroughly wash the flask with dish detergent, and then rinse under running water.
Just like citric acid, this product effectively cleans plaque and eliminates unpleasant odors inside the thermos.
Pour vinegar and hot water in a thermos in a ratio of 1 : 3. Close the container, shake the contents and leave for 3-6 hours.
Then shake the thermos vigorously again, pour out the liquid and wash the flask with dishwashing detergent. After that, rinse the thermos with clean water.
The soda contains orthophosphoric acid, which dissolves impurities quite effectively.
Pour the cola into a saucepan (determine the amount of the drink by the volume of the thermos). Put the container on the fire and bring to a boil. Pour the hot soda into a thermos, cover it with a lid and leave it overnight.
Pour out the coke and wash the flask using dishwashing detergent. Rinse the thermos with running water.
There are no tricks in caring for the outer part of the thermos. Usually, washing with a soft sponge with dish detergent easily copes with external dirt.
If there are still contaminated areas like greasy spots on the container, they can be wiped off with a cotton pad soaked in vodka, ethyl alcohol or vinegar (9%). After that, wash the thermos with dish detergent and wipe it dry so that there are no streaks left.