I wouldn't worry too much about the apple juice as long as it is fresh pressed as the benefits of malic acid appear to out way the Sugar content. Malic acid can also be found in sour cherry juice which contains about 5 times as much consequently you should be able to consume less and still get the same value for the liver flush.
There are a number a medical papers being produce of the back of Fibromyalgia research that would indicate malic acid may reduce the influence of Candida especially when taken with magnesium. This is because tartaric acid which is a by product of yeast interferes with our body chemistry and malic acid helps address that imbalance.
Flushing should help to restore your body’s chemistry to its optimum balance.