People use mouthwash to reduce tendencies of bad breath. Moreover, mouthwash has some properties which kill known bacteria residing in the mouth. It is one effective way to rinse the mouth and therefore, it promotes good oral hygiene. Twenty five percent of the Americans have halitosis, a chronic bad breath. About seventy percent suffers from periodontal disease which includes periodontitis and gingivitis. Therefore majority of the population found the release of mouthwash in the market very helpful. Aside from the mouthwash's chief task to cleanse the mouth off any accumulating bacteria, it helps with their social activities. There are times bad breath tends to stop people from talking to others. But with the help of mouthwash, people tend to be more confident while interacting with others.

Mouthwash ingredients include thymol, eucalyptol, hexetidine, methyl salicylate, menthol, chlorhexedine gluconate, benzalkolnium chloride, cetylpyridinium chloride, methylparaben, hydrogen peroxide, domiphen bromide, fluoride, enzymes and calcium. There are also water sweeteners such as sorbitol, sucralose, sodium saccharine and xylitol. Some mouthwash has alcohol which takes up to 27% vol. The alcohol content gives an antibacterial effect. According to research, alcohol causes mouth to be dry. It also aggravates the condition of chronic bad breath. It decreases saliva, which naturally makes breath fresh.

A researcher from the Dental Journal of Australia published a report linking mouthwash to oral cancer. It concludes that there is enough proof that alcohol-based mouthwash increases the chance of having an oral cancer. Alcohol based mouthwash has acetaldehyde as its by-product. As Acetaldehyde is produced, it builds up in the oral cavity. The researcher believes it is carcinogenic, thus causing cancer.

However, some dental experts are still firm on their contention that mouthwash reduces mouth infection as it kills bacteria residing in the mouth. That until now, there is no extensive report released evidencing mouthwash as a cause of oral cancer.

Oral cancer happens when a cancerous tissue grows in the oral cavity. Oftentimes, oral cancer is commonly found on the tissues of the lips and the tongue although it may also happen in the floor of the mouth, lining of the cheek, gums and palate.

In 2008, around thirty four thousand Americans were diagnosed with oral cancer. People with oral cancer often experience a burning sensation whenever they eat spicy foods. As their condition worsens, they find difficulty to open their mouth. These are because of the lesions which are present inside the mouth as a result of the cancer. Smoking and alcohol are the recorded top reasons why people at risk of oral cancer. There is an even bigger risk when a person drinks and at the same time smokes heavily. Drinking and smoking have both a collaborative consequence on oral cancer. This is the reason why some recent study closely linked alcohol-based mouthwash to oral cancer. As an alcohol-based mouthwash is gargled, it leaves Acetaldehyde, which enables substances causing cancer (e.g. Nicotine) to get through the linings of the mouth with no trouble. However for now, there are still no extensive evaluations which can show valid proofs that gargling with mouthwash is harmful.