The first step involved in cleaning cat urine stains from upholstery is to find the actual location of the stain. This is done with the help of a black light. The wet stain is absorbed using a paper towel. Rubbing should be avoided because it tends to spread the stain. A paper towel with weight added to it should be placed over the stain to absorb the liquid effectively. It is rinsed preferably with warm water. The affected area is then treated with an enzyme based cleaner. After applying the enzyme product, the affected area should be covered with aluminum foil. The carpet should then be rinsed and washed according to the label instructions.