Same here! Sometimes we'll leave some seasoning and herbs in the aluminum so the fish can cook in it, too. I guess that doesn't make it much different from simply cooking over the stove, but we usually do it when we have other food to grill just to save propane. It's definitely important to properly grease surfaces that'll be in contact with the fish, even fish in broth ends up sticking to the inside of our aluminum foil, lol.