1. Baking Soda: Use baking soda, Baking Soda has this ability that it makes mouth a bad living place for bacteria.
2. Chewing Gum: If you use non-sugar chewing gum your bad breath will go away. Why ? because your mouth will produce saliva when you chew gum this helps to kill germs. This research was done by scientists of University of California. Also chewing mint leafs and fennel Seeds helps in reducing bad breath.
3. Diet: If you eat more protein foods it will make your breath bad and worse if you eat high protein foods and sleep with out brushing your teeth your breath will stink. The reason is that high protein foods increase the production rate of germs.
4. Green Tea: According to scientists green tea contains polyphenol which helps to kill mouth germs and this tea does not let's you have bad breath.
5. Artificial Mouth Wash: These are in wide use these mouth washers are also effective use it when ever you are going out.