As educational institutions grapple with questions about increasingly complex Artificial Intelligence (AI) systems, finding effective methods for explaining these technologies and their societal implications to students remains a major challenge. This study proposes a methodological approach utilising Conceptual Metaphor Theory (CMT) and UNESCO's AI competency framework to develop activities to foster Critical AI Literacy (CAIL). Through a systematic analysis of metaphors commonly used to describe AI systems, we develop criteria for selecting pedagogically appropriate metaphors and demonstrate their alignment with established AI literacy competencies, as well as UNESCO's AI competency framework. Our method identifies and suggests four key metaphors for teaching CAIL. This includes AI as a funhouse mirror, a map, an echo chamber, and a black box. Each of these metaphors seeks to address specific characteristics of GenAI systems, from filter bubbles to algorithmic opacity. We present these metaphors alongside pedagogical activities designed to engage students in experiential learning of these concepts. In doing so, we offer educators a structured approach to teaching CAIL that touches on aspects of technical understanding and provokes questions about societal implications. This work contributes to the growing field of AI and education by demonstrating how carefully selected metaphors can make complex technological concepts more accessible while promoting CAIL.