To give you the best advice, it would help to know: Is this a commercial or residential urinal? Is it a water-flushing or waterless model? How severe is the blockage/odor?
To dissolve urine crystals (uric scale) in urinals, you must enzyme-based cleaners specific descaling acids
Flush the urinal multiple times or pour several gallons of hot (not boiling) water down the drain to wash away the dissolved sludge and remaining acid. how to dissolve urine crystals in urinals
Method 3: The DIY Household Solution (Vinegar and Baking Soda)
This is the most critical step. The chemical needs time to break the molecular bonds of the scale. For light buildup, 15–30 minutes is sufficient. For severe blockages, let it sit for several hours or overnight. To give you the best advice, it would
Muriatic acid (hydrochloric acid) is highly effective at dissolving stubborn calcium and uric scale, but it is incredibly corrosive. Only use this as a last resort. Do not use muriatic acid if you have old metal or chrome plumbing, as it can eat through the metal. It should generally only be used in PVC plumbing systems.
A urinal auger features a specialized rubber guard to protect the porcelain bowl from scratches. Insert the spring-loaded cable into the urinal drain. Crank the handle clockwise while pushing forward gently. To dissolve urine crystals (uric scale) in urinals,
Best for severe, thick, old scale where the deposits have been "mineralized" with hard water or when enzymatic cleaners have had limited effect. Care must be taken to use a product designed for porcelain.
When you encounter resistance (the crystal blockage), rotate the handle repeatedly to break the scale apart mechanically.