believe that the coil could be damaged and then break at the becket. Cleaning strings that are dangling out of a customer's piano in their lounge is not an ideal scenario, but I have done it many times, taking every care to use appropriate covers and towels as required. Accidents are simply not permitted to occur! If the strings are removed, they are threaded individually on to a coat hanger wire in the order that they are removed, and the ends of the wire securely joined so they don't slip off and get mixed up. The strings are then slipped into a paper "Kleensak" and taken away for cleaning. Note. If it is decided that a new set of wound strings should be ordered from the manufacturers, it is essential that the piano serial number is quoted along with the model. The wrong size strings were sent to me once and it was discovered that the piano manufacturers had altered the stringing configuration part way through the production of that same model. The strings were too long causing the windings to extend over the hitch pins. Because I had initially quoted the piano serial number - which they had not checked - they were obliged to replace the strings with the correct set, at no additional cost. Cleaning. The strings are hung outside on a clothesline and simply hosed down. This will get rid of a large proportion of the black residue. The strings are separated as best as possible