I've used LJ-Sec previously to import my LJ posts to IJ, but the original use for the program is to mass edit post settings, eg. making public posts private, or filtered, or deleting multiple posts. I used it on LJ to make older posts private, and it worked fine (with just a bit of scrolling down the list of posts and selecting the ones to edit). I can't imagine it not working for DW, though I haven't tried it.