The only way to eliminate calculus build up is by brushing and flossing frequently. It takes pyhsical removal of the placque before it calcified into the hard tarter, or calculus. Some people will have more tendency to build up calculus because of the chemical composition of their saliva.
Brasso is a metal polish designed to remove tarnish from brass, copper, chrome and stainless steel. It is available either directly as a liquid or as an impregnated wadding pad.
Brass is usually made up of copper and zinc. Some alloys are called bronze when they are actually brass, such as commercial bronze which is made from copper and zinc. Other metals may also be added, but if the main addition is tin, it's a bronze, and if the main addition is zinc, it's a brass.