Others may already know this, but I just stumbled onto it this week. My water pump was out of service for about 3 days and water was being dispensed rather miserly, except for drinking. A jug was used to rinse the toilet after flushing, but the urine odor quickly became overwhelming. I started spraying the toilet after rinsing with various cleaners.
Mean Green Orange Champ does an amazing job on neutralizing urine odor. So much so that I was able to skip the water rinse and just release the the liquid into the black tank and spray the empty bowl. I use wet wipes instead of TP which goes into a covered trash can, so no water is needed just to flush the TP.
I found a great deal on Amazon
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Just be aware that this cannot be shipped via USPS.