My Adco lead removal cloth says "Not for use on blued or Nickle finish". It works wonders on stainless but, I am afraid to use it on the cylinder face of my nickle Smiths.
I recently bought Lead-Clean Gun Cloth made by Pro-Shot Products. The label states to use only on Stainless or Nickel finished guns. Do NOT use on blued or case hardened surfaces. Worked great on my nickel 29-2 cylinder face. proshotproducts.com