Given the myriad pads available for Scotch-brite cloths, this is NOT TRUE. UNLESS you go into the GROCERY STORE and buy one made to scrub pots and pans.
MSC Industrial Supply Inc (machine shop supplier) lists eleven types of Scoth-Brite pads (one for mild - will not mar glass, ceramic, fine china, PORCELAIN, TEFLON, SILVERSTONE or formica surfaces - that Light duty #63 - will certainly NOT HARM your blued surface).
Scotch-Brite also makes High Performance Cloths that I like better than their Cleaning Pads - considerably more expensive ($6 vs $2) BUT much softer than even the #63 listed above. They use microfiber structure reduces and sometimes eliminates the need for cleaning solutions.
There are others that will take the paint off a battleship. BUT, if you know WHICH one you need AND HOW TO USE IT, these things are the best thing since sliced bread.
Finally, ASSUMING YOU DO REMOVE SOME FINISH accidentally from your BLUED firearm, use either 'Perma Blue' or 'Aluminum Black' (my choice) made by Birchwood. Use a Q-tip to apply until you are satisfied with the results.