Poor oral hygiene is bad, bad breath is posisbly the most offensive and revolting of the lot, far worse than crooked or stained teeth. So it makes sense to take it seriously when you smell your breath and find that it smells quite bad. There are over the counter medicines that cost quite a bit for what they are (esentially mouthwash with a couple drops of hydrogen peroxide).

The truth is you can buy the ingredients easily from the supermarket and make your own powerful anti hallitosis mouthwash. You can buy the cheap supermarket brand mouthwash from all leading supermarkets, a large bottle typically costs less than a dollar. Then you can buy hydrogen peroxide and water based solution which contains 5% hydrogen peroxide.

For oral use, you should aim for 0.5%, so take one serving of mouthwash out of the bottle and pour an equal amount of the hydrogen peroxide soluton and you have a great halitosis mouthwash.