All education is either propaganda or training for a position in the workforce. Training for a position on the workforce is straightforward to understand. Propaganda relates to instilling the belief system, values and historical revisionism of a specific country, state, religion etc. It also includes in more refined systems of educational propaganda more subtle undermining of the inquisitive human faculty by such as teaching us to believe we are being taught useful thinking techniques. Really this subtlety is being used to stop us questioning the other taught stuff and, more worryingly, presenting restrictive means of thinking as pure ones.
When taught critical thinking, and let’s be honest why is there a need to teach something that is natural unless it is an attempt to amend or restrict the natural way, the first things to consider are who is teaching this, why, what is the aim of what is being taught and what are the restrictions of the technique. Surely if taught honestly the first thing critical thinking would stress would be to critically assess the notion of critical thinking and for that matter any form of education. However, the teaching of such things is not motivated by honesty.
Always be aware of the primary goals of any institution and how these will not impact positively on the human condition.