We once had a generalized urine smell in a house, and we had ripped out everything but the ceiling, hoping it was not that.

Any court would find pet urine and feces to be considered damage.

depends on situation. grey water is just shower sink, can go into ground. soon will convert to composting toilet so poop and urine separated. can throw away bagged poop as done with poopy diapers and dump urine. no black water.

There was urine and poop on the pads and the floor.  

If that liquid has an odor like pet urine or alcohol it stays with you for a long time.Just my nickel

The reason I entered was because when I went to pick up the rent check the community enclosed front porch reeked of animal urine.

I've used a product called OdorXit on pet urine and was happy with the results.

In my case the tenants have allowed their dog to ruin my wood floors by urinating and vomiting on it for an extended period of time without making any effort to repair or stop the damage.

It was an excellent learning experience.The house was in pretty rough shape all around, but the smell from decades of smoke and dog urine were horrible.  

After the tenants finally moved out, they left damages far beyond the security deposit - a total of 40 drywall holes, sharpie drawings all over the walls, broken doors, broken kitchen cabinets, urine soaked carpets, you name it.