He points out that the wax makes an excellent fluid condenser and picks up the "vibe" of the spell which is patterned by the prayer or invocation, and released through burning. Another thing that helps this process along are using candles of different colors and shapes. Different colors have different vibrations that will amplify a corresponding intent. This is the same in using colored Chi or Prana in different types of healing.
Some people have pointed out that in the old days, there were no colored candles, everything was just beeswax - ergo colored and shaped candles are not necessary for magic. True enough, but nothing is necessary for magic. Tools are there to help you along and make a process easier and more effective.
Those that see magic as something that was perfect in ancient times, and which we only have mere shadows of today will want to reconstruct things to be as archaic as possible. People that see magic as a living and evolving thing that gets better as time goes on will want to take advantage of newer traditions and perhaps make some advances themselves. It should be no surprise that I fall into the latter camp.
Above is picture of a double action reversal candle that is being burned in the appropriate manner, ie: you cut the top off, turn it upside down so that the black side is up, dig out the wick and burn it that way. The black part of the candle reverses the negativity back to the sender whether this is another magician, a spirit, or just the universe itself. After that is cleared, the colored part strengethens whatever was weak: white for health, red for love or lust, green for money, etc.
Do not underestimate a simple candle spell. In the hands of a skilled worker that spell from the $2 Anna Riva book is as potent as a Goetic evocation. In fact its often more potent because the person doing the candle magic will actually do the work, whereas most ceremonial magicians talk more about goetia than they actually do goetia. Frater RO is someone who clearly understands this, and is one of those that will take advantage of both and really do the work.