I had a look at it but it seems 'too much in the head' for me, lol. But that'll be because I'm more into folk magic and hoodoo type magic. It's my thinking that mental magic manifests only mental results.
I believe that there are basically three levels (for want of a better word)- mainly the Akashic realm or the realm of the divine, the Etherial level and then the level of the material world where we are living our everyday lives.
When magic is worked any or all of those three levels can be incorporated into your magic. Prayer is one way to incorporate the divine level into your magic. The energy on the etherial level can be channeled through your body or use the energy of the elements. And material from the material level could be something like a candle or herbs/oils.
I think for strong magic, all of the levels should be incorporated into your workings for the best results.