The interior of your piano should be out of bounds to you and your family. Any dealings with your piano’s interior should be handled by a qualified piano technician.
Every 2 to 3 years, depending upon the exposure to dust and dirt to which your piano is subjected, the interior should be cleaned by a professional. If this step is neglected, you run the risk of exposing the piano’s complex inner workings to undue wear at the hands of abrasive dust and dirt particles. If a pencil, coin, hairpin, or foreign object of any kind should fall into your piano it should be removed at once by a professional piano technician. Foreign objects can seriously affect the action and tone of the piano.
Polishing should be handled by a professional. Cleaning the piano should be done with a slightly dampened cheese cloth or shop towel. Wipe in one direction, particularly in the direction of the grain of the finish if your piano has one; never use a circular motion. Do not use solvents or furniture polish of any kind and keep all dampness away from the keybed and strings. Placing plants, vases, pictures, or any object on the piano may have a ruinous effect on the finish. Lastly, NEVER spray any kind of liquid directly onto any surface of the piano; instead, always dampen the cleaning cloth directly.