It is effective, not deemed torture-at least not yet-so unlike waterboarding it is legal-I have been told recently-and gleefully-about a couple of occasions where it was pushed a bit over the limit with a smug suspect-but it did get the info needed...
I can’t remember which movie it was, but a suspect was going to be interrogated by the two main character detectives.
The suspect said something like, “I ain’t fallin’ for that old ‘Good Cop / Bad Cop’ routine!”
Whereupon one of the detectives said, “Good! Because that was so old we don’t use that anymore!”
Suspect, “You don’t?”
Detective, “No!” Throws chair at suspect and hit him. “We now use ‘Bad Cop / Worse Cop Routine!”...................