Well I'll put my 2 cents in and hope it helps ..I have been able to remove light mold/mildew odors from my books by following the advice of a bookseller I met while waiting in line for an estate sale. You put the book in a sealed plastic bag and put it in the freezer overnight to kill the mold, then remove the book and lay it out in the sun (not direct sunlight which might fade the book, but late day sunlight) with the pages fanned out for a few hours - the smell should be reduced considerably. This of course, doesn't work well with books that smell strongly of cigarette smoke and I have never tried it on really really smelly books.