Stains can be removed or hidden on the fabric of couch cushions, but the stuffing in the couch cushions will continue to hold odors long after stains are removed. If a new couch is out of the question and sprays and odor neutralizers are not working, consider taking apart the couch cushions to clean the stuffing without harming the fabric of the couch cushions.
Remove the cover from the couch cushion. Most cushions will have zip-off covers that are easily removed and replaced. Pull the covers off and launder the covers while you are cleaning the stuffing.
Dilute bleach in a bathtub full of the hottest temperature of water you can get from the tap. You may need to run the water for a while and allow it to heat up before you begin catching the water in the tub.
Fill the bathtub half full with hot water, and then pour in a full gallon bottle of bleach. Pour slowly to prevent splashing so that you do not damage the clothes you are wearing.
Place the foam or other type of stuffing from the couch cushion in the water. Push the cushion below the surface of the water while wearing rubber cleaning gloves to prevent irritation to the hands. Push the foam cushion stuffing or other stuffing types below the surface to completely soak the pieces, and remove air bubbles so the stuffing is less likely to float as it soaks in the tub.
Allow the cushion stuffing to soak for several hours. Wearing the gloves again, wring out the pieces and take them outside to air dry.