Stains can build up over time in a urinal, caused by everything from hard water to rust. Normal urine stains can be removed from urinals using a scrub brush and some commercial toilet cleanser; vertical stains are probably mineral deposits. Different stains may need different treatments. Because of the verticality of urinals, soaking the stain in a solution for an extended period is not as much of an option as it is for bathtub and sink stains; therefore, a manual approach is more desirable.
Replace the intake line if the stain is rust; otherwise, the problem will return, spoiling all your hard work.
Remove rust stains using a wet pumice stone. Pumice is harder than rust but softer than porcelain, so you can scrape away the rust without risk of scratching the porcelain of the urinal. Pumice is an effective stain remover, without the use of harsh chemicals.
Remove hard water stains with a paste of borax and lemon juice. By not adding too much lemon juice, the mix is paste and can adhere to the vertical walls of the urinal. Do not apply the paste with bare hands. Leave it for 15 minutes before rinsing. A less noxious option is to lay paper towels soaked in white vinegar on the urinal walls for 15 minutes. A pumice stone is also effective for scrubbing hard water stains.
Use a pet urine remover to remove old urine stains too stubborn for standard toilet bowl cleanser. Such solutions include an enzyme to break down biological stains. A pumice stone is also effective for urine stains.
Restore the urinal's shine with paste auto wax or a window cleaner like Windex.
Don't use abrasive cleaning products on porcelain, since they might scratch. Make sure the pumice stone is wet before scraping with it. Avoid bleach, since bleach and urine form a noxious gas. Also, bleach can etch porcelain if left on too long.