Though you might be out of luck, it should be noted that the wowhead article and the blue it quotes appear to be out of date. This is from the hotfixes on the 27th:
Torghast, Tower of the Damned
- Any Soul Ash that was not looted from defeated enemies will now be sent directly to your character’s currency collection the next time you log back into the game.
Thread here: Hotfixes -- Updated March 12