My 6 month old puppy chews everything in the house, but only when we are asleep or not home?

I've tried firmly saying no, swatting her lightly when she chews at night and I catch it. I've tried redirection to toys - we spend at least a hundred dollars a month on puppy chew toys that she just destroys right away. So I bought one that's supposed to be indestructible, but she doesn't chew it for long because she can't tear it apart so she moves on to something new. I lock her in the main kitchen/dining area but she just chews on furniture now. How can I get this to stop? I thought about the spray, but she's taken to chewing my books as well and I can't spray those! Please help!!