Any number of herbs (when taken in moderation) can help fight off candida. Black-Walnut is great because it contains natural tannins which is great for killing of candida.
You could also try barberries (contains berberine which has anti-microbial properties). Burdock root is great for purifying the blood, echinacea is a great natural antiseptic & immune boosting herb.. and of course, there's garlic - which is another natural antiseptic and has been known to bolster good bacteria whilst killing off bad bacteria.