This is what often needs to be done after a person and their cats have moved out of a place. It is the process of removing all dander and fine fur from a house or apartment, so that people with severe cat allergies can live their without taking a constant supply of allergy medication, and having their asthma triggered.
We really needed to decatify the apartment before moving in. Before we decatified the apartment, even after the professional carpet cleaners and cleaning crew came in, I kept on sneezing and wheezing. When I washed down the walls and rinsed off the wash cloth, loads of fine fur and dander was suspended in the water. Gross!