RE: Lemon juice cooks meat?
It doesn't cook it. It reacts with the proteins and firms up the flesh. It is in no way cooked, except for the fact that most food-borne bacteria don't like highly acidic environments. Additionally, highly acidic marinades will eventually denature the proteins and the meat will become grainy and crumbly. In any event, there is no such a thing as a marinade that will cut your cooking time.