Builder, to answer your question why we use alkanet. Stains will color the wood but will not be absorbed as deeply into it.
when a repair needs to be done like touching up a scratch and the wood is sanded the stain will be sanded as well, leaving a light spot. Even when stain is re-applied to this spot it usually will not match the surrounding color and appears to be lighter. The red oil penetrates deep and can be sanded leaving the same tone.