If the urinal is completely clogged and the liquid won't go down, chemicals cannot reach the crystals. You must mechanically break them up first.
Marco plunged the urinal to push standing water down the trap, then used a wet-dry vac to remove the last inch. Crystals dissolve best when the cleaner isn’t diluted. how to dissolve urine crystals in urinals
For stubborn uric acid crusts: Use a pumice stone wet with acid – dry pumice scratches. If the urinal is completely clogged and the
If you are cleaning a home urinal or a weekly maintenance schedule, skip the heavy acids. skip the heavy acids.