Regarding the idea that the use of odd numbers forms some sort of defining tradition in hoodoo: This is not true.
The number 4 is used in hoodoo among many practitioners, especially those who are of Native American descent.
See HOODOO LUCK-BALLS (JACK-BALLS) by Mary Alicia Owen, 1893
http://www.southern-spirits.com/owen-ho ... balls.htmlThe use of 4 candles around a central object is often used to define a Christian cross or a crossroads on an altar. See the photo of 4 candles around the spirit trap by ConjureMan Ali above, and the photo of the circle divided into a cross by Deacon Millett above -- and also see this picture from the AIRR web site:
http://readersandrootworkers.org/wiki/Ancestors:

In this photo, which features the work of Prof. Charles Porterfield, we see that he had laid out graveyard dirt from the graves of four different ancestors, all of whom were buried in one family graveyard. The dirt was then scribed in the form of a crossroads. The four candles defined the territories or graves of each of the four ancestors, and each area contained individual offerings: a cup of tea, a bowl of chocolate squares, a mini-bottle of whiskey, and coins. A fifth candle -- not part of the 4-candle ancestor array -- marked the way forward or the outcome of the work.
Thanks to the Association of Independent Readers and Rootworkers for permission to use this picture for educational purposes. If you wish to engage the services of a professional rootworker, you should look up these and other members of AIRR at their own group web site:
http://readersandrootworkers.org