Salt can purify the water in the thermos engine-grease
Can't, you can use vinegar, preferably white vinegar, put a little, shake, good ~
Want to use acid, with vinegar, or go to the market to buy special except alkali powder
Sure no, yes with vinegar.I recommend using toothpaste, try the best
After thermos with long, the bottle will give birth to a layer of scale, it is not easy to remove. Thermos if in dilute hydrochloric acid, tightly capped bottle caps, shake gently, and then let stand for 30 minutes, rinse several times, can remove scale.