Junio, soda is great for cleaning, but as for the musty smell, you might need an ozonator. But you need to be careful with it. Ozone can be harmful to YOU. Long term exposure to ozone is bad for plastic and rubber. You'd need to put the couch in a small room, turn on the ozonator, close the door, seal the bottom of the door with a towel and leave it for a few hours. Then you'll need to hold your breath and open a window to clear it out.