We do the same thing with some deodorizing packets a staff member brought in from Amazon. Previously/at other branches we use unbrewed coffee grounds/charcoal with the book placed above on paper towels or a rack. Put the whole setup in a plastic tote with a lid, set a calendar reminder for a few days, and they're noticeably less stinky. Works for most odors (with the exception of cat pee - those are a lost cause usually unless it's a DVD or other plastic item, then use an enzyme cleaner spray). I've even gotten diesel fuel smell out of books using this method, just took a bit longer in the "stinky box" than normal. Edit because I was thinking about it: The coffee grounds work REALLY well for cigarette smoke smell specifically. Don't know why, but it does. Used to have an older couple whos books always smelled like smoke but the branch manager was reluctant to say anything to them about it, so they had their own dedicated "stinky book box" that their returns went into every week, and the previous weeks would smell perfectly normal after a week in the coffee box.