It depends on your classification of effective. If it is to gather accurate information, it is ineffective. If it is to gather the justification for what you were going to do anyway, it can be most effective.

For a fairly recent example: the US' post-911 War on Terror when they were waterboarding people. This definitely didn't get them any real info, and they found out in the worst way that innocent people will confess when they think they are actively dying.

Prior to this, it was already known to produce false feedback and confessions. The US military has a strange way of repeating history to see if it'll turn out differently "this time." It sadly never does.