Well y does Naka suggest this? I know boon says to do it now but y would others say this other way.
Several reasons, his SoCal climate is one, cutting the candles (step 3 below) means the internodes are cut to a length you determine, but it is an older technique. As I mentioned, some clarification on what is meant by "decandling" will help this. The technique you're referring to is illustrated in Naka's "Bonsai Techniques II" book, pp 231-234, read this for a better understanding.
1. It states to remove all candles over 1" long in the spring. By the illustration, it is clearly before the needles begin to appear along the candle. In my climate, it looks like mid-April.
2. A month later, reduce the resulting buds to a pair (ideally, they'll be at the 9:00 and 3:00 positions) of candles, and let them grow.
3. In the fall, SHORTEN (not remove entirely) these 2 candles so that only a few pairs of needles remain. The cuts are made horizontally, cut-side up.
4. In the following spring, new buds appear between the needles that were left in Step 3.
5. Repeat the process.
In my opinion, this stresses the tree twice a year at critical times; once when that spring flush is removed, and then again when the candles are shortened in the fall, removing next year's buds. This also forces the grower to work with weak growth. Summer candle-pruning only stresses the tree once, but it's after the new growth has had a month or more to "charge up the batteries" first.
Does this make sense?