It’s been used as a cleaning solution, as an antidote for gonorrhea, a sterilizer during surgery and now is used to fight off bacteria and halitosis. The oxidation of bacteria though the use of a rinse is one of the easiest ways to sterilize an environment, which is why the method has been used for odor control in the mouth since the naissance of Listerine in 1879 as a surgical antiseptic.

Mouthwash has grown from its humble origins to a product that fills a variety of needs. With it carries a variety of consequences. Dr. Philip M. Tierno, Jr. Director of Clinical Microbiology and Diagnostic Immunology at Tisch Hospital, New York University Medical Center surmises on some emerging issues having to do with mouthwash, including alcohol versus alcohol-free washes.

When mouthwash first came into existence there was no non-alcoholic variety. Even today many mouthwashes contain alcohol. However, continual use of a mouthwash containing alcohol can bring about some negative effects as well as positive—including cancer. Similar to those who contract mouth cancer associated with an over consumption of alcohol, riding oneself of bad breath with wash containing alcohol may also be a cancerous trigger.

“The alcohol may kill on contact pathogens,” said Tierno about the short-lived benefits of mouthwash containing alcohol, “but in the area of microbiology you also get a rebound affect.”

The alcohol in the bacteria fighting liquid serves as a desiccant or drying agent. This may not be a positive thing since saliva serves as a natural defense against the overgrowth of bad breath causing bacteria.

One simple solution involves diluting the wash with water, or using alcohol-free rinse. This type of odor control wash may be made with different constituents than mouthwash with alcohol, such as cetylpyridinium chloride, but it still has virtually the same bacteria killing impingement.

Hydrogen peroxide one-percent can also be used in killing unwanted bacteria on the tongue. Depending on the extent of the problem one part water can be combined with one part hydrogen peroxide for extreme cases and diluted to two to three parts water for more minor conditions.

Other positive factors having to do with alcohol-free mouthwash include decreasing the risk of alcohol poisoning for those with small children and alcoholics. The consumption of mouthwash containing alcohol, by people with alcohol problems is a situation so obscure that it is easy to overlook.

Original Listerine is approximately 26.9 percent ethanol alcohol. It is made up of ingredients that are supposed to make it difficult to drink, though drinking it is possible.

One case was documented on The Straight Dope. In response to a question about the possibility of ingesting mouth wash, though no direct source was given, one man reportedly died from ingesting three liters of Listerine.

Other cases having to do with alcoholics drinking mouthwash or cases where mouthwash is substituted when alcohol is difficult to obtain are prevalent on the internet simply by typing the words “drinking mouthwash” into a search engine.

An article in the Seattle Times on the 28th of June included a 40 year-old recovered alcoholic who wrote in about his last drink involving mouthwash.

“This last-ditch effort to resort to some form of alcohol that wasn't a “real drink” was what convinced me that I was a hopeless alcoholic,” said the anonymous recovered alcoholic supported by columnists Joe Graedon and Teresa Graedon, PhD in the Peoples Pharmacy section who concurred that the act is a serious sign of addiction.

Despite the problems associated with it mouthwash does is beneficial in maintaining proper oral hygiene. It’s even been suggested that mouthwash maybe used by people who are unable to regularly brush and floss in order to cut down on the number of decay causing pathogens in their mouth.

Mouthwash companies have been eager to develop alcohol-free alternatives. These also have not been without their growing pains.

In May 2008 the alcohol free mouth rinse product manufactured by Hydrox Labs of Elgin, Illinois and Cardinal Health Inc. of Dublin, Ohio was recalled after testing positive for the Burkholderia Cepacia bacterium. This organism was cited as a possible trigger for infections in people with weak immune systems or chronic lung disease by the Food and Drug Administration.

One year earlier, in April, 4 million bottles of Listerine product "Agent Cool Blue" were recalled for potential contamination. The product, aimed at detecting plaque in children, was found to be contaminated by microorganisms. The incidence of actually suffering a reaction due to the contagion was low aside from individuals with a weakened immune system.

Newer mouthwashes have been largely a success, however. They have even helped to fight rather than cause mouth cancer.

A January 2008 article in Reuters released news about research performed at Johns Hopkins Kimmel Cancer Center in Baltimore regarding a mouth rinse developed to spot mouth and throat cancers in people with high risk including heavy drinkers and smokers.

Research about the “swish-and-spit” test published in the Clinical Cancer Research Journal identified cancer in more than half the people who actually had it, though it may be years before the product is actually released.

As the evolution of mouthwash gargles along, the human race may be rinsing its way to better health.