Most permanent and most expensive solution is a humidifier... Dryer sheets rubbed over the couch should help, though.

Static when brushing horses is a problem and I diluted liquid fabric softener about 1/3 to 2/3 water to lightly spray my horse - something similar could work on the couch, but I'd try dryer sheets first because I wouldn't want to get it too damp!
The pews never miss a sermon but that doesn't get them one step closer to Heaven.
-Speckla

But at least the pews never attend yoga!