I am not too familiar with this technique but a quick google search revealed that it is about visualizing what you want and getting rid of the things (e.g guilt about getting what you want) which stand in the way of what you want.

I cannot see much difference between this method and the Law of Attraction which basically teaches the same principle that if you give enough thought to something, then it has to manifest in your reality as long as you do not stand in the way of it (by feeling the lack of it or the guilt of having it).

So, in answer to your question, this method is both a mind control and a spiritual based method as you have to have control over your thoughts and what you manifest. In doing that, you get more aligned to the non-physical being you are at a deeper level. This is because when you have any desire or want, this want or desire is already manifested in the non-physical world and the fact that you can allow the manifestation to happen in your physical reality implies that you are in allignment with your inner being (your non-physical self) which is a spiritual experience.

Hope this helps.