Cleaning your piano is an important part of keeping its tones pure and resonant. It is relatively simple to dust the wood and keys, and internal oiling and tuning should be left to the professionals. However, you must also service your piano strings, or piano wires, every once in a while. Although they are usually protected inside the piano, the strings can begin to tarnish and weaken after a period of time, which could eventually cause them to snap. Preventing this is a simple matter of cleaning your piano strings about once a month.
Open your piano housing to expose the strings. On a grand piano, lift the flat and hold it in place with the hinged prop under the flat. On an upright piano, remove all music books and the music shelf from the front of the piano. Lift the front of the piano and hold it in place with the hinged prop or with a rubber-ended yardstick.
Rub each wire very gently with steel wool. Find steel wool without detergent or cleaning solution in it; this will corrode the strings and undermine your efforts. If your wires are very close together, it is okay to rub several at a time with a larger piece of steel wool.
Dust away any steel wool bits you can see with a soft cloth. Remove remaining steel wool with an air compressor by directing a stream of air behind your piano strings and blowing the bits to where you can remove them. You can also use a brush-head vacuum attachment. Hold it close to the piano strings and suck up as many steel wool bits as you can.