I'm not sure if a 12 year old can put in the 120% commitment needed, but I went to both. HCRI was useless for me (I have yet to meet anyone who says different), and Mcguire is a great course. Getting him used to pausing, diaphragmatic breathing, and avoidance reduction should go a long way into uprooting the chance of becoming an avoider later in life, etc. The sooner, the better.