For years Brasso was the last and only word in products for cleaning brass.  For small flat surfaces Brasso works pretty well if the residue is thoroughly cleaned off.  Often with church brass, surfaces are rounded, etched, indented and not flat –  and Brasso has a tendency to lie in crevices and cracks and turn green if residue cleaner is not completely wiped away immediately.  There are several good products on the market but the best results may be obtained with MAAS which comes in tubes, bottles or cans and can be used for multiple types of metalware.  MAAS is found in most auto stores like Auto Palace, hardware stores or from home stores.  MAAS does not turn greenish, is easy to work with using a soft cloth or toweling and does not require a lot on the rag to get the job done. It does not have an odor.  To lacquer or not to lacquer?  Any brass church flower vase should NOT be lacquered.  Constant exposure to water and minerals contained in water will pit and peel lacquer within weeks of having containers relacquered. Items which are seldom handled such as large altar crosses, lecturns, etc. are better candidates for lacquer treatment.  Candlesticks, which are constantly handled and cleaned of dripping wax are much easier to keep bright if not lacquered.