Quality Vs Quantity
While Kane broke into a cold sweat at the prospect of being a test subject in the R&D process of Rui's technique projects, Rui continued to flesh out the technique.
To read the subconscious mind, he would put his victim in a trance where the subconscious mind had greater primacy over the body, conveying greater amounts of information through non-verbal communication.
To put them in a trance, he would need to apply hypnosis, distracting his opponent's conscious mind and awareness to leave their subconscious mind exposed. And then, he had to implant the classic hypnotic suggestion of sleep. Of course, this would not cause them to actually sleep, but it would put them in a minor trance where their subconscious mind's influence and control were magnified.