Treating water marks is like treating a cough.
The cough can be from a cold, noxious fumes or chemicals in the air, or throat cancer.
The water stains that Tony (Harryhides) and I recommend distilled water for are those caused primarily from sizing that has migrated from a spill or improper spotting.
Other events that can create water marks are a ring of soil from attempting to only remove a spot on a piece of upholstery that should be completely cleaned, cellulose browning, and color bleeding to name a few.
You need to determine the problem first, then you can find the best solution to correct the problem.
I'd hesitate to use Stain Magic for Wool on cellulose fibers (its not called "Stain Magic for cotton/linen/rayon" after all). Bleaching, even with non chlorine bleaches that contain peroxide, should be used only as a last resort, as it may weaken these fibers.