I gave up trying to find local entities that would take and use my old books so I have since either shipped them to a group who distributes them in Africa (
https://www.mobileread.com/forums/showthread.php?t=17422) or else dumped them in a recycle bin. I don't think Reader's Digest books are what they are looking for. On the other hand, maybe someone who wants to do one of those crazy book art things (where they cut the book up and do something creative with the remains like this:
http://centripetalnotion.com/2007/09/13/13:26:26/ ) might be interested.