Oral Rinses
The first line of defense against bad breath is a variety of oral rinses, or mouthwashes. It's a simple idea really: you take a mouthful of the solution and swish it around in your mouth, making sure you get it into every little nook and cranny, and even gargling with it to expose and wash the tissues at the back of the tongue and the top of the throat. When the solution contains something that kills or physically dislodges oral bacteria, it can be quite effective at reducing the unpleasant odor of bad breath.
Oral cleaners are tools for mechanically removing the same troublesome bacteria. Tools like toothbrushes, tongue cleaners, and similar products make valuable partners for oral rinses in a good oral hygiene program. Tongue cleaners scrape a layer of noncellular material and oral bacteria off the tongue, physically removing them from the mouth (One drop of this material can contain literally billions of microscopic bacteria, so this kind of scraping can make a significant difference, especially when it is done regularly.) Toothbrushes and other handheld scrubbers for the teeth remove plaque, which is a buildup of mineral deposits, food particles, other proteins, and a healthy population of bacteria that are thriving in tiny crevices there.
Some commercial brand names include a whole line of oral products including oral rinses and oral cleaners. Some even market their products in kit form, so that you can get the tools and the first bottles of mouthwash at a better price. Once you have everything you need, you only have to replace the mouthwash as you use it up. Tongue cleaners don't last for ever, of course, but they only need to be replaced periodically. Kits are probably a practical approach if you can find one that you like.
Many people just settle for oral rinses, adding the use of mouthwash to their routine a couple of times a day. When the mouth is healthy, and the person hasn't got a serious problem with bad breath, this approach is probably perfectly adequate; however, if there is a chronic problem, and the bad breath is the really bad rotten egg kind, much better results will be obtained by using oral cleaners as well. It should go without saying that when there is a chronic underlying problem, such as gum disease, even oral rinses and mechanical cleaning will have limited effect - see your dentist or doctor to get some professional help with reestablishing a healthy mouth. Fresh breath will probably follow.