Yes, if they are galvanized bars you will never get them totally clean. It absorbs the urine.
If they are coated.... I think the absolute best odor killer is a diluted bleach solution. Just make sure to rinse very well. I spray on with a spray bottle, then scrub down, then rinse.
You can also spray on 100% white vinegar. I alternate between vinegar and the dilute bleach, as the bleach can corrode even coated bars over a long time.
And a product called Nature's Miracle works well but its too expensive to use every week for cleaning.