This subject has been covered before and there is nothing new to add at this time, however, new laryngectomees using a voice prosthesis could find the information useful.
Candida is the yeast infection which colonises the voice prosthesis and eventually causes leakage of liquid into the windpipe and/or makes voice production difficult. There are a number of strategies you can adopt to eliminate or at least control candida. Take Nilstat “Nystatin” oral drops; an eyedropper comes with the bottle, swill an eyedropper full around your mouth, and gargle, for at least four minutes before swallowing. Use as often as you consider necessary, personally I use it once a day before going to bed. Also available in tablet form is Fungilin which in my case proved the most effective.

When changing your prosthesis, coat the inside of the internal flange of the fresh prosthesis with Daktarin Oral Gel before insertion. The removed prosthesis should be thoroughly cleaned and then soaked in Hydrogen Peroxide solution or Milton for at least 24 hours. Always rinse thoroughly after soaking, and always use a fresh solution each time you soak a prosthesis. As you can see it pays to use two prostheses in rotation. Bear in mind that Hydrogen Peroxide is not specifically recommended by manufacturers and may even degrade the silicone, however, I have never experienced any significant problems.

Reduce your consumption of alcohol, especially beer. Cut down on lollies, cakes and sugary foods. After drinking beer or eating cakes drink water or lemon juice to rinse your mouth. A good idea is to keep a jug of water containing slices of lemon in your fridge. You can use a syringe to clean your prosthesis in situ. Squirt water through the prosthesis to flush out food particles and liquids which contribute to yeast build up.

Reflux can also encourage Candida growth, slippery elm powder mixed into a little milk or a number of proprietary remedies can be used to combat this Acidophilus yogurt is a good way to finish a meal with a view to attacking Candida, Vinegar has also been suggested to me (revolting but Cider Vinegar with a little honey is quite palatable). Also Pro-Biotic tablets (Acidophilus)
An indwelling prosthesis is now on the market which has a small amount of silver oxide in it. Silver oxide is known to have anti-fungal properties and so should help limit yeast development. This product is now showing up in the clinical population and more should be published about the effectiveness or otherwise of the device. The ‘Voice Master’ prosthesis from Holland has a body which consists of a titanium sleeve which is apparently resistant to the growth of Candida.