Is it bad to wipe over surface with mold on if it doesn't come off on the cloth and then reuse cloth?

For what?: You are using the cloth to wip surfaces. I assume you are not talking about sterile surfaces in a laboratory. Are they surfaces on which you intend to prepare food? Have you ever seen TV shows shot in restaurant kitchens? Noticed that the prep tables are all stainless steel? Wondered why? They can pour boiling water on them and scrub them clean if need be! Non-food areas not as important.