Full disclosure: I did a very dumb thing in trying to solve this problem, and I did it on purpose.
Don't do the dumb thing I did. Which was boot into a working live environment, unmount
/, and then
#dd if=/path/to/iso.img of=/path/to/former/root.
What does this do? Kills your MBR (makes your computer unbootable).
Fortunately, I have a separate partition for
/home, and I did the dumb thing on a personal computer, so I didn't loose any files that I'm particularly attached to (farewell,
/var/log & friends!) but now I get to enjoy the dubious pleasure of trying to reconfigure my entire OS.
How I managed to actually solve the problem originally posed in this post was by taking the desired ISO and running the
isohybrid command on the image, then
dding it to a USB drive... et voila! Bootable, Slacky goodness.