I actually bought my Bar Keepers Friend for use cleaning vintage Pyrex, but saw a blog post somewhere touting its ability to clean stains on the exterior enameled surface on LC pots.
I moistened my thick paper towels and sprinkled on the BKF, then started scubbing gently. After one cleaning, I was starting to notice some improvement. I gave it a quick wash to see if the enamel lost any sheen, but it was fine. I gave it a second round, scrubbing a little harder.
Anyone else used BKF on Le Creuset with success? I am pretty happy with it, and might tackle another scrubfest this weekend.