I've been playing with ways to filter all the mail from Facebook so as little of it as possible is actually ever in my inbox. Instead, it's landing in a separate mailbox where I can skim for what I need to see. There are a few addresses messages come from that I can filter on; one they stopped using a couple of years ago was "wallmaster." :-)
Now that I've filtered most of that to a separate mailbox, I've deleted all but the last few months worth. I clicked a couple of "___ wrote on your wall" links and found some amusing old stuff, but that way lies madness.