IMO it is not so much an issue of belief as it is an issue of intent. We know the mind acts on suggestion and intent. If someone goes into a Photoreading class with the intent to prove it does not work it is very possible that they will not get it.
Using an NLP example, I read an article in one of my brothers' magazines (I forgot the title) which "proved" that Speed Seduction doesn't work. The reporter went to a bar and used the patterns and failed. His problem, though, was that all he did was memorize canned patterns and did not learn calibration, tonality, rapport, hypnotic language patterns, anchoring, etc. Even worse, he went into the situation with the intent to prove it wrong and that surely showed up in his non-verbal communication and his "energy." In a sense he "hypnotized" himself to fail.
