Animal and human urine can be the hardest thing to remove from upholstery for several reasons:
1. Usually the urine has saturated the cushion as well as the material, so the cushion also has to be extracted and treated.
2. Cat urine is full of pheremones. This is an identity scent designed to smell for a long time and the scent molecules can be smelled at a substantial distance from the source.
3. Human urine is sterile (acidic) when fresh, however it can smell pretty acrid when the bacteria get to it.
So, what should you do? In most cases minor contamination can be remediated professionally. This does not mean simply cleaning the material. Remember the cushion. Also spraying deodorizers on the source does not work and will only temporarily mask the smell. If you love your couch, let a pro deal with it.