Fill a bowl with water and a bunnnnnch of ice, then add a ton of salt and put it in the freezer. Keep it in there as long as you can without it freezing. Then drop the fish in and it should stop moving within 1 second.
Pretty much instant. I then leave it in the freezer for a while to be sure.
librarygirl said:I could be wrong, but not sure this method would work well with goldfish as they are coldwater fish. It might if the water is cold enough but it probably won't be as quick as doing this with a tropical fish. The clove oil method might be better.