This is a question that comes up from time to time from some of our customers. While it is difficult to determine the exact longevity of the cloths, we can safely say that one cloth will polish a silverware service for eight or a brass tuba!
I recommend that customers use the polishing cloths over and over again until they disintegrate, regardless of how discolored they become. When the cloths begin to discolor it is not necessarily dirt that appears on the cloth, but rather a transfer of tarnish. But, not to worry this transfer of tarnish from metal to cloth is a one way street!
If the cloths should become dry then a few drops of vegetable oil or mineral spirits will revitalize. Do not wash the cloths.
Interestingly enough, I have found that the more discolored the cloths become the better they work. And to prove this a customer sent us a cloth after 5 years of use! Now that's getting your moneys worth.