I took a polygraph about 30 years ago a Ft. Meade during a background check for NSA. Honestly it took like 45 minutes, guy was totally pleasant and he treated it seriously, but it seemed mechanical, strictly scripted, and more like a box checking exercise.

However, I also had an interview with a psychologist which was very intense and manipulative, but effective, in eliciting true information about how much I was drinking at the time (too much, quite frankly). It was only years later that I realized that was the information they really wanted and all the other embarrassing sex questions were just to set me up.