salicylate has some anti-plaque action, but less than chlorhexidine. Methyl salicylate does not stain teeth. Nystatin Nystatin suspension is an antifungal ingredient used for the treatment of oral candidiasis. Potassium oxalate A randomized clinical trial found promising results in controlling and reducing dentine hypersensitivity when potassium oxalate mouthwash was used in conjugation with toothbrushing. Povidone/iodine (PVP-I) A 2005 study found that gargling three times a day with simple water or with a povidone-iodine solution was effective in preventing upper respiratory infection and decreasing the severity of symptoms if contracted. Other sources attribute the benefit to a simple placebo effect. PVP-I in general covers "a wider virucidal spectrum, covering both enveloped and nonenveloped viruses, than the other commercially available antiseptics", which also includes the novel SARS-CoV-2 Virus. Sanguinarine Sanguinarine-containing mouthwashes are marketed as anti-plaque and anti-malodor treatments. Sanguinarine is a toxic alkaloid herbal extract, obtained from plants such as Sanguinaria canadensis (bloodroot), Argemone mexicana (Mexican prickly poppy), and others. However, its use is strongly associated with the development of leukoplakia (a white patch in the mouth), usually in the buccal sulcus. This type of leukoplakia has been termed "sanguinaria-associated keratosis", and more than 80% of people with leukoplakia in the vestibule of the mouth have used this substance. Upon stopping contact with the causative substance, the lesions may persist for years. Although this type of leukoplakia may show dysplasia, the potential for malignant transformation is unknown. Ironically, elements within the complementary and alternative medicine industry promote the use of sanguinaria as a therapy for cancer. Sodium bicarbonate (baking soda) Sodium bicarbonate is sometimes combined with salt to make a simple homemade mouthwash, indicated for any of the reasons that a saltwater mouthwash might be used. Pre-mixed mouthwashes of 1% sodium bicarbonate and 1.5% sodium chloride in aqueous solution are marketed, although pharmacists will easily be able to produce such a formulation from the base ingredients when required. Sodium bicarbonate mouthwash is sometimes used to remove viscous saliva and to aid visualization of the oral tissues during examination of the mouth. Sodium chloride (salt) Saline has a mechanical cleansing action and an antiseptic action, as it is a hypertonic solution in relation to bacteria, which undergo lysis. The heat of the solution produces a therapeutic increase in blood flow (hyperemia) to the surgical site, promoting healing. Hot saltwater mouthwashes also encourage the draining of pus from dental abscesses. In contrast, if heat