Oregano just kills Candida. Here is a write up I did concerning this:

If you are trying to fight Candida killing the Candida is not going to work. First of all Candida is a natural part of the body.  And trying to kill the Candida just leads to rebound growth.

As I pointed out, Candida is a natural part of the body.  Normally the immune system keeps the Candida in check primarily through the production of acids (lactic, acetic and fatty acids) by the beneficial flora. These acids turn off the Candida growth gene, and keeps the Candida in its relatively harmless yeast form.  In an alkaline environment the Candida growth gene is turned on and the Candida is converted in to its highly aggressive and pathogenic fungal form.  In its fungal form the Candida develops finger-like growths called hyphae that allow it to dig in to tissues where it can cause damage to tissues and organs.  A simpler explanation is that the Candida only becomes a problem when the immune system is down allowing the Candida to overwhelm the immune system.  Antibiotics are a common trigger for this problem as antibiotics kill off the acid forming Lactobacillus bacteria.  This shifts the pH of some tissues in to a more alkaline state that allows the Candida to survive and thrive.

The trick to getting Candida under control is to get the immune system back in control.  A good start to this is with probiotics, like kefir, and prebiotics, such as rice bran, oat bran and FOS.  Yucca root is another good choice as it helps to kill the yeast while making a more suitable terrain for the growth of the flora.

Stress also adversely affects the immune system, which again helps Candida to thrive.  There are many aspects to the immune system, but a couple of primary areas to focus on are the flora and the adrenal glands.  To address the adrenals vitamin C is the most important.  The B vitamin pantothenic acid is the second most important nutrient for the adrenals.  Adaptogenic herbs are excellent for building up the adrenal glands.  These include schisandra berries, licorice root, suma, ashwagandha, Siberian ginseng, and astragalus.  As you build up the adrenals you will also find that dealing with stress will become easier as the adrenals release more anti-stress hormones.

Zinc is also essential for proper immune function. Recommended dose is 50mg once daily with a large meal to prevent nausea.

Maintaining proper stomach acidity is essential as acid kills yeast and alkalinity is its friend.  Stomach acid naturally declines with age making Candida overgrowth of the digestive system very common. The zinc I mentioned will help in the production of stomach acid.  B vitamins (B6, B12, folate) are also essential for the production of stomach acid.  So a B complex is also recommended twice daily with meals.  The problem is that these nutrients are also acid dependent for absorption.  So the declining stomach acid actually interferes with the absorption of the nutrients needed to produce it.  To get around this it is a very good idea to take something acidic with your meals to enhance absorption. These can be non-buffered vitamin C (ascorbic acid), citric acid, or malic acid.  In addition I recommend trimethylglycine (TMG), derived from beet leaves, 3 times daily, which among other things will boost the immune system and help the body to generate the digestive secretions it requires.  It can be a little hard to find, but some health food stores carry it.  TMG runs around $11 a bottle.

Avoid anything that alkalinizes the stomach acid.  This includes antacids, acid blockers, magnesium oxide/hydroxide, calcium oxide/hydroxide (lime), baking soda and alkaline waters.  Stomach acid is one of the body's first line defenses against pathogens.  Neutralizing it is just asking for problems.