Right, and that shouldn't be banned.
Really? Because that's basically the premise behind all of the truth serums listed in the topic article.
There's no such thing as a true truth serum, but rather intoxicants similar to alcohol that loosen people up and confuse them while you tell them that it's a truth serum.
Who cares if you give someone alcohol and tell him it's magic sauce? How is that torture?
Well, you're forcing psychoactive chemicals into them, which many would contend.
Forcibly giving someone ethanol and telling them it's magic sauce is currently illegal. I mean, there are other substances too, but as Wikipedia says, most of them simply make the person more talkative and confused.