I would personally remove all traces of urine first:
- Clean and descale urinal (including underneath and pipework)
- Clean and descale walls (including grout if tiled)
- Clean and descale flooring (including grout if tiled)
If the urinal is a trough style unit, check out the edging, especially underneath as the uric scale will build up and cause bad odour problems. This may require a large screwdriver to chip it all off first, then apply acid to take all traces away.
If possible, turn off water supply to urinals and then remove pipes/wastetraps and clean them out.
Same for the W.C areas. I would clean all areas, W.C, wall paneling, doors, corners and grout etc.
This would eliminate the odour at source instead of masking the odours with chemical and would require this work to be carried out periodically to eliminate the odour and keep the area hygienic.
Hope this helps.
Many might not agree as they would prefer the quick way out and mask with urinal blocks and air fresheners.