Cesium only partially replaces potassium in human metabolism, and that increases with higher doses of cesium, but what you need to understand is the healthy human cells need potassium to function (regulating blood pressure, etc.) Therefore there is no way to "starve" candida of potassium, because you would then also be starving you healthy human cells of potassium.
Cesium chloride works well against cancer, but not by starving cancer cells of potassium. That's not how it kills cancer, and I suspect that is also NOT how it kills candida.
Candida fungal infection as far as I know may, or may not cause cancer. Not enough is yet known about cancer. It is common in cancer patients and leukemia especially, strongly resembles severe fungal infections. Candida and fungus usually thrive in acidic conditions and cesium chloride reduces acidity. This may be why it works well to control candida and/or other fungus'. Acidic conditions in the body are caused by EXCESS sugar, grain, soda and meat consumption. Fruit and vegetables reduce acidity (i.e. alkalise the body.) - as does cesium chloride.