It improves taste, aids digestion, prevents throwing up oil, and it positively afects all internal organs.
2. What if someone's allergic to citrus? Can they just use oil?
Yes yoy can, but it is easier to get oil down if you use some other fruit juice, like pineapple juice, or apple juice, or granat apple juice or any other freshly pressed sour juice from any other sour fruit or berries (blueberries, blackberries, raspberries, ...).