Sir, we have read Dr Dagher and Dr Hannan's letter about mouthwash in the recent issue of your journal.1 They have suggested restriction of mouthwash advertisements or limiting mouthwash use with prescription only as use of mouthwash influences oral and general health.1

Dr Singh and colleagues have suggested that copper may help to prevent Streptococcus mutans infection in the oral cavity.2,3

Mouthwash use is also associated with a slight increase in blood pressure and risk of head and neck cancer.4,5 Copper present in drinking water stored in copper tanks kills bacteria and the copper content in drinking water stored in copper pots is within the permissible limits (177±16 ppb) of the World Health Organisation.6 Hence swishing of drinking water stored in a copper tank may be a help as a safe economical mouthwash which can be used by the general population.