Railroading sucks. There's really no way to sugar-coat this; if the DM can't handle the players choosing a different path than intended, he's just not any good. Using an all-powerful NPC to prod the characters into line is even worse. It begs the question, why are the players even there? After all, if the characters are going to do the same thing no matter what, the DM could play by himself...
I played in a one-shot campaign once, with a DM I knew. He gave us pre-generated level 1 characters (under the circumstances, not that bad of a thing). As part of the backstory, my character had had repeated dreams of falling off a cliff, so one of the spells he had learned was Feather Fall.
So, guess what happened? Yep, he had me fall off a cliff. Didn't matter what I rolled, didn't matter that I said I was staying far back from the edge, somehow he'd find a way that I'd go over the edge, because he needed me to find the secret cave in the side of the mountain.
Anyway, to the original topic: activating a command-word item requires a focusing of will, like these guys said. Activating 6 wands requires six separate actions. Otherwise, if I had 9 wands in my backpack and one in hand, they'd all go off when I triggered.
