Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Only Automatic Dish Soap Works

The only way to clean a Thermos is Automatic dish soap and boiling hot water. Shake every five minutes for 20 minutes and it will be as clean as a whistle only way to clean a thermos. Does not clean the side of the Thermos because it is too stiff and it will not even clean the bottom. I scrubbed for half an hour and looked into the thermos and the bottom only had a small area that was clean...So this looks like it will work but it won't...