Ok I recently found this trick out and did a search for it and didnt find it the same way on this website. What i did was I hit log out, as the timer was ticking down as soon as it hit 1 and was bout to hit zero i typed /afk. Next thing i knew i was logged out, once i logged back in was out of the BG and had no debuff.
Tested in WSG and EOTS, sometimes you just log out if you dont do it at there right time.