I do agree that Water Absorb is more reliable, but Cursed Body has provided me with some really great possibilities during some random wi-fi matches and the Battle Subway- for instance, switching in a Vaporeon's Ice Beam, disabling it (sure I was lucky that it activated immediately, but my point remains) and then having a safe switch to Jarooda.
And that's just one situation. I can remember quite a few others, too- I've stalled a Buffaron until it ran out of Stone Edge PPs, then Cursed Body disabled its Earthquake and I switched to Abagoora and forced a switch, allowing me to set up a few Curses and sweep.
Of course, it sometimes just refuses to activate. But it's not like I'm relying on it- when it happens, it helps a lot. When it doesn't, no big deal, since Burunkeru is still doing his job of walling special moves, recovering itself and burning stuff.