In western Japan where kinpaku butsudans (Buddhist altar heavily lacquered using gold-leaf or gold lacquering) are common, warosoku is preferred because the carbon content in its smoke is lower than that of western candles and therefore warosoku is less likely to stain the gold leaf.
西日本では金箔仏壇を使用する例が多いが、和蝋燭の煙に含まれるカーボンが洋蝋燭に比べ少ないので、金箔を汚しにくいためである。