It is usual to flush directly following a parasite cleanse. It must also be the case that your urine and bowel movements are flowing normally. Some people who didn't have good kidney and bowel function have suffered a secondary reaction despite having a "good" flush.
The apple juice is a preparation and although it adds the flush it is not essential. You just need the Epsom Salts , olive oil and lemon/grapefruit juice to flush successfully.