Nothing stinks quite as bad as tom cat spray and this woman didn’t know the cat was spraying the wall? Good grief! She must of had no sense of smell at all!
You know, I wondered that too, but I could not smell it either. She must have been using that spray that covers up cat pee.
I only saw it when I pulled out my flashlight and shined it along the wall and then wiped a wet paper towel across it. After getting wet you could smell it.
After that, I bought one of the UV flashlights and put it in my tool bag.
My grandad had a male cat. One day it sprayed his LP record collection. Twenty years later you could still smell the cat urine on the sleeves. (valuable collection - one is an original Beatles LP, first one out).