I know the feeling. I have a black lab. I use just the hose. No attachment. It takes some work but I found that to work the best. Or duct tape works to. Not as good though. I started to put towels down until my seat covers cane in. Good luck.
There is this thing i bought for my furniture in my house, its a little blue thing wuth a bunch of like fingers coming off of it, that you just rub of it and it kinda gathers it up. It looks like this, but its blue. It wors AWESOME, got it at the dollar store for 2 bucks and is one of the best things i have bought, lol