These are a couple of methods the professional products use for treating urine odors and also for cleaning up urine soaked areas. You might as well take your tips from the pros because they do know what works.
The first version of urine treatment is done with enzymes, you can get gallon sized jugs or spray bottles of these cleaners at any pet supply store. Just spray it in the bowl as your cleansing rinse. It will neutralize the urine and also it will reduce the odors on the surface and in the holding tank. A lot of the eco friendly, commercial enzyme treatments for holding tanks are based on this technology. You can buy it in a powered form or in a liquid form. I have been using the Kids and Pets brand sold at pet stores and grocery stores for many years for cleaning up accidents from various dogs and cats too. Also used for rinsing out the litter boxes and cleaning the floor around the litter boxes. It works very well for human urine or the urine of other animals as well. If you ever get a mouse problem then use this stuff to wash your RV interior and areas of the exterior too to remove their urine trails that can attract other mice.
The second method the pros use is hydrogen peroxide. It is a great cleaning disinfectant which is used in many household cleaning products and it does neutralize odors and clean surfaces. You can make your own diluted solution of it by purchasing bottles of jyrdrogen peroxide from drug stores and in the aisles of the drug store where first aid supplies, dental supplies, etc are sold. You can also buy it in bulk in a powder form from feed and seed ranch supply stores and make your own spray bottle solution. They use it for cleaning the urine odors out of stables and kennels. Of course this it is the same thing as the Oxy clean, Oxygen bleach, cleaning products and you can purchase off brand versions of it from the dollar store for another bargain friendly choice. It might be in powdered form or it might be sold as a pre-mixed solution in a spray bottle.
The nice thing is neither of these methods leaves behind that truly obnoxious smell that is Pine Sol. In my opinion the smell of that stuff is just about as nauseous as the smell of the urine. But of course we all have differences in our olfactory processing for both physical and emotional reactions to various thing.