Oh no, dealing with cat pee on a sofa cushion is a frustrating but very common issue for cat parents! Don't worry, you can definitely tackle it.
First things first, it's a great idea to check the cleaning tags on your couch or cushion for any specific warnings before you start. Different fabrics can react differently to cleaning solutions.
If the accident is fresh, the most important initial step is to blot up as much of the urine as possible with a clean cloth or paper towels. Press firmly to absorb the liquid deep within the cushion. Avoid rubbing, as that can spread the stain.
Next, you'll want to use a cleaner specifically designed to break down the uric acid in cat urine, which is what causes that strong, lingering odor. These are often called enzymatic cleaners. While a solution of vinegar and water can help in a pinch, an enzymatic cleaner is your best bet for completely eliminating the smell so your cat isn't tempted to mark the spot again.
Thoroughly saturate the affected area of the cushion with the enzyme cleaner. You need to make sure the cleaner soaks as deeply as the urine did. Let it sit for the amount of time recommended on the product's label, then blot the area again with a fresh, clean cloth. Allow the cushion to air dry completely. It might take a while, but this is a crucial step. Once it's dry, give it a good sniff. If any odor remains, you may need to repeat the process.
