Hilchos Chanukkah / Kindling the lights (r) – 25

1. All types of wicks are acceptable for the Chanukkah lights, but to fulfill the mitzvah ideally, the wicks should be of cotton or flax(ShulchanandMishnah Berurah673).

2. Edible oil (i.e., not bitter) that was left under the bed, may not be used for Chanukkah lights [nor Shabbos lights], since it was affected by aruach ra’ah(negative spirit). But bitter oil that is not edible at all is not affected byruach ra’ahand may therefore be used for kindling(Kaf HaChaimad loc.).