To light candles in Hanukkah is not kosher (ritually perfect) because the miracle it celebrates was about one day oil lasting eight days. So it has to be oil and not candles. What kind of oil? In those times, only olive oil was used. May one use eating olive oil sold in the supermarket? No, only highly refined olive oil, like the one used in the Temple of Jerusalem, can be used. In the past, I used olive oil but my wife disliked the practice because it smells and candles are cleaner. Between authenticity and peace at home, I choose peace.