Here by matter or material includes even ideas and inference because they all stem from mind and mind is built of subtlest matter (as per Samkhya philosophy upon which Raja Yoga is based).
The method to experience of consciousness in Raja Yoga is not consequence free – direct experience of ones own consciousness is the best experience a man can have, and it transforms him thereafter forever. Also read Kundalini by Gopi Krishna.
The process itself is far from boaring and you'll be surprised the changes/experiences you start to observe within few weeks/months of starting the enquiry. (But beware of scammers who sell trademark techniques!)
Btw, I'm not professing any religion here. It's just that there's a method of enquiry which many people throughout the history have attempted and they have experienced something which you also can provided that you dare to. (Samkhya philosophy in fact denies existence of God as we know it but only professes idea of pure consciousness)
Swamij.com is also a good read for curious folks. I have been researching and practicing for some time. I have good number of proofs which modern science has recognized, plus my experiences of last few months. I plan to write an article on this some day. .