[image: faster panda kill kill]
First off, we'd air out any of the pieces that are removable from the couch for a few hours at a minimum, giving them some good wacks with a broomstick or whatever you can use to dislodge as much of the dust being housed within. Then we'd thoroughly vacuum the upholstery using a HEPA vacuum, followed by a thorough soak using a pet odor removing formula like Nature's Miracle or Get Serious. You may want to also rent an extractor or wet vac from a local hardware store to thoroughly rinse out the formula using plain water.
We don't recommend steam cleaning if there is any chance urine is the cause of the smell, because the heat sets in stains. You might want to use a black light to look for invisible pet urine stains on your upholstery.
One bit of advice we've heard that makes a difference is using a HEPA certified air purifier while your washed upholstery is drying. A well designed air purifier should include an odor removing element; if you can afford it, there's nothing quite as effective as the IQAir models in our experience.