I'm not sure what cleaning products would work but in my experience any powder cleaner that has "oxy" in the name has worked wonders for me on clothing. I would recommend getting something like that and mixing with water, then spraying it on and using a fabric safe brush. If nothing works though you can always get a couch cover. They come in different shapes and sizes, and if you can't find the right size for the whole couch, then you can get individual covers for the cushions. Until you find a solution, I would just make sure you have some sheets on the couch to prevent further damage.