[flnastyax]

I haven't heard of this technique, but I have used a similar one which I read about in "Astral Doorways" by J H Brennan.
It consists of making cards (white background) with a coloured shape on them (square, triangle circle etc). Each shape has a specific colour and meaning.
These cards are then stared at for a few minutes. This leaves an imprint (Afterimage) on the eyes in the complimentary colour of the shape.
This shape is then used in a visualisation. You see it as a door and visualise your hand stretching out, opening it and then walking through the door.
This was the first technique I ever tried and it worked first time.
Each ‘doorway’ is supposed to lead to a specific area of the astral.
In my own experience, the imagery wasn’t absolute. It was more like an overlay visualisation – not a total sensory immersion experience. But the experience was cohesive and structured.