Copper pots are used to store water for drinking purposes. Research shows that copper is a great way to store water as it conditions the water stored in it because of its anti-bacterial and anti-fungal properties. When water is stored and used after 4-5 hours, the microbial activity in the water is proven to be lesser than the initial levels.
Copper pots can be cleaned using tamarind pulp and sea salt mixture to remove the blackish stains. After which a regular dish wash agent could be used. Clean with a dry cloth and leave in sun light for 20 minutes before filling with clean water again.