The stainless steel drinking cups should be thoroughly cleaned once a day. The cup surface, inner tank, and bottle cap should be cleaned to prevent dirt from being generated. If odor and stains have already occurred, don’t worry. The following are the cleaning steps: Before this, we would like to introduce 3 ways to remove odor inside the stainless steel cup. Salt to remove odor. Pour salt into the thermos cup, dilute it with hot water, shake it well, soak it for 5 to 10 minutes, and then rinse it off. Baking soda to remove odor. Dilute the baking soda with hot water, pour it into a thermos cup, seal the lid, shake the thermos cup, and rinse with water. Lemon to remove odor. Put lemon slices and lemon juice in the thermos cup, add boiling hot water, soak for about an hour, and then wash with a sponge. White vinegar has the same effect as lemon. The first step: wash the inner gallbladder to remove the odor (choose one of three from the above list). Step 2: Clean the gap of the bottle cap. Remove the lid of the cup, squeeze some toothpaste on the toothbrush, gently brush the gap of the bottle cap, and then rinse with clean water. Step 3: Rinse with clean water as a whole. Rinse the whole inside and outside of the cup with clean water. Step 4: Wipe dry. After washing, it should be thoroughly dried and then covered to prevent the stainless steel thermos from smelling.