I had the same problem when I found out Addison had tapeworm. I gave him medication and had to clean EVERYTHING. At that point, he only had one bed and spent half his time in that, half his time in my bed. I washed the sheets easily enough, but his bed was a bit of a problem. I would say take it outside and shake off as much of the hair as you can, and whatever doesn't come off that way, do it by hand. If you don't have a roller hair remover (I don't) use tape. I find its pretty easy to wrap a piece of tape around your 4 fingers and just press here and there, occasionally spinning to a clean piece of tape.
I still had some hair left when I washed it but figured if the washer didn't get it, the dryer would. Most of it came off, but there was still some left. I'm sure after a year of hair build up, anything will be an improvement so don't worry if there's still a bit. Give it a day or two and it'll be hairy again anyway
