It would be nice if there was a rule allowing unwanted books to be destructively scanned and put online in the public domain.

Maybe publishers could have the right to purchase the books back at current list price or something if they want to block the shredding.

I like the premise but it sounds like something where the overhead in trying to track & manage that would be overly burdensome for all parties until you just forced more reasonable terms on when material enters the public domain in the first place, at which point such a system wouldn't really be needed anyways. The last thing I want to see to try to clean up public access to work is even more complex rules and systems being layered on top of the existing system.