The Leather Cleaner that kill my bag by removing its dye

Not all leather cleaner including those popular brands is suitable for removing stain off your leather bag. See below pic on how the dye of the bag has been removed when the owner attempt to remove the ink mark using the leather cleaner.

If you have to use a leather cleanser, try at a small area first as most cleaner tend to be rather abrasive. We also suggest using the conditioner and steer away from all sort of leather cleaner.