He is a complete idiot! No understanding of the science or the functioning of the disease. Once the virus is in your lungs, no matter how much lemon-water you drink has no effect on the virus. Keeping yourself hydrated is important, use whatever you like in water (lemon, ginger, honey, etc) for taste but it won't kill the virus. Eat a balanced diet, and exercise regularly to stay fit. Eventually, its your immune system that will overpower the virus. If you have symptoms, then isolate yourself in a room and rest properly, do not exert yourself.