Polygraphs do not work that way

They're based on detecting shifts in pulse and breathing based on subliminal, usually-irresistible fear of being caught. You can throw them off by doing something as simple as sticking a tack in your shoe and pressing on the point with your toe every time they ask a question (or being a sociopath). You know what would utterly ruin a polograph? Waking up with a shotgun stuck in your face.

Oy.