Ozonated water or drops of 35% Hydrogen Peroxide in water will both give some benefit for both candida and ulcers.Food grade hydrogen peroxide can be bought from health food stores here in North America but I can't say where you'd get it SA.Ozonated water must be made fresh with your own ozonator so you would have to purchase one. There are a lot of places online to buy them. Take a look at my article Ozone Generator 101 at http://www.ozonatedoilonline.com/articles.html
to learn about ozonators.
Happy Due Diligence!