I've been airbrushing a whole piece of mohair - using the copic system. It has left the mohair not quite as soft as it was and I wondered what would happen if I wash it now!? Has anyone else tried? I've used multiple colours and don't want them to run!!!!!!
I've found a good way to soften airbrushed mohair is to pop it in the tumble drier on a cool setting with one of those fabric softener sheets. It gets rid of any chemical smell from the ink too. I would'nt leave the mohair in the dryer for a long time just in case it overheats and all your hard work will go to waste!
I do lots of airbrushing with acrylics and it is totally washable once it is heat set. As far as the copic markers go, I do know that they feel stiffer than acrylic airbrushed paints but I don't know if they are color fast. I like Penny's idea. You could also try cutting a small piece of your painted mohair and hand wash it to see what happens. Heck, if the inks run it might even make a really nice effect...ya never know!