Brush away any soot or debris from the books with a paint brush.
Sprinkle baking soda generously between the pages of each book.
Add a couple of tablespoons of baking soda or activated charcoal to a plastic bag. A few handfuls of cat litter will work as well. Prepare one plastic bag for each book, and put the book inside. Be aware that charcoal may stain so do not use it for books whose covers you are concerned about.
Seal each bag tightly by tying a knot in the top or using a plastic bag tie.
Place the bags out of direct sunlight and leave for up to a week.
Remove the books, dispose of the baking soda and check if any odor remains. If so, add fresh baking soda to the bag and leave for another week.