http://sn.1w6.org/file/mk-20140629T184532-anxfe5q.html
@mcscx yes, as a non-desctructive approach. but as I already have pulled off all the data that can be pulled off, I'm going to do a 'scrub' instead. But even my previous test run may have improved things a little - I just don't have a list of blocks from that. after the current testing run, I am going to pull off a list; then I'll scrub, and then I'll get another list to see if there's any difference.