I use Natures Miracle for cat stains. But my cat has to eat a special prescription cat food (CD) and it has no additives or dyes, so the stains are just a dull yellow that is easily removed when he yacks. A lot depends on the kind of cat food you use. If you feed them kibble that has been dyed to LOOk good, such as "Kit and Kaboodle" or "Whiskas" (there are many others, just cant think of them all!), then you will get very reddish brown highly staining yacks!
So better food = easier to clean yacks.