Targeting one at a time allows your body to process and remove the toxins from each organ - doing them together will make you ill due to the huge amounts of toxins being puled out. Sometimes slower is better.
The liver flush - like you have done - is much like taking your car to a car wash - whereas - the liver cleanse formula is like taking your car for a complete tune-up.
The flush washes out toxins and stones - and the liver cleanse formula has herbs that contain natural chemicals to deep clean and stimulate the liver - much like a tune-up.