He's right and wrong... rendering it almost useless?!?! uhhh, no!
There is ephedrine with guaifenesin in it, which is the same stuff found in Robutussin. The theory is it makes the ephedrine look more "legit" from a legal aspect. Some say it's a mild muscle relaxer, but I've been taking it for seven (yes 7) years on and off pre-workout without ever having any problems. And it gives me the "ephedrine high" I'm looking for. Stack that with caffeine and aspirin and you're good to go.
You can find ephedrine an almost any convenience store here on the east cost. You can also find it on-line, with and without the guaifenesin. I see no real difference as the half-live of guaifenesin is 1 hour. But still, I've never seen or felt anything from the guaifenesin.