Spritz the area with clean water. Blot the urine spot with a clean towel. Soak up as much of the urine as possible.
Sprinkle baking soda over the urine stain. Use enough baking soda to completely cover the urine stain.
Mix a cup of water with a drop of dish detergent. Avoid dish detergents with bleach or bleach substitutes.
Pour the water and dish detergent solution over the baking soda. Pour enough of the solution so the baking soda reaches a thin, paste-like consistency. Don't add so much water that the baking soda becomes a runny liquid. The amount of solution used depends on the size of the spot.
Scrub the baking soda paste into the urine-stained couch. Use a scrub brush to work the baking soda into the crevasses of the fabric.
Allow the baking soda to dry. Once dry, it becomes a loose powder again.
Vacuum the baking soda up. Blot the area with a clean, damp towel to remove any stubborn particulates.
Spritz the area with a 50/50 mixture of vinegar and water. The acid in the vinegar removes any lingering odors from the couch. Once dry, the vinegar smell dissipates.