We have the same problem with our son. I couldn't figure out where these trails of waded wet paper balls were coming from, until I found some in my son's mouth while holding his corners chewed board book. We read him his stories mostly now holding the books... he can't hold the book (paperbacks or hard covers). When he has a board book we watch him and as soon as he brings up the corner to his mouth, we say "no" with a mad face. He gets upset and tries again when he thinks we're not looking, but that's when we say it again, but take the book away. He's learning, but teething is a pain and anything is comforting for him to chew on. With that being said, we now limit his toys(no books) to what we ALLOW him to chew on. You probably should take the bath book out, because that is very dangerous. She could accidentally swallow some plastic.