I have a Duo Masters Degree for piano and voice performance. (not bragging) If you are trying to save your voice, sucking on a fresh halved lemon is good for breaking mucus build up in your voice box. Sucking on a lemon however will affect your ability to smile convincingly. Warm water with fresh lemon juice squeezed into it is also helpful. Cooking lemonade juice? I am not familiar with it by that name. Do you mean bottled lemon juice? If so, forget about it. It's some pretty inferior stuff. I'm not really sure what the percentage of that particular concoction is lemon, bu-you-you-you-you-you-t by the way it tastes, maybe 1%? It's nasty. As a child when I or anyother of my siblings had a sore throat my parents would combine equal parts of vinegar and very hot water for a gargle. That also was nasty. I don't really remember if it helped my throat, but the taste alone would cure me of my throat ills. The best thing you can do for your voice is to speak in natural tones. Avoid yelling, screaming or hollering. And one of the biggest wears and tears on your voice is talking a lot. After all that, no you can't lose your voice drinking lemonade. But lemons help to loose your voice of any mucus buildup.