Does sure slim work as a diet?

You can only get an opinion for this question; and the overwhelming opinion seems to be that 'diets' such as you describe do not work. However, this does not mean that you would not successfully lose a few pounds this way. There is no substitute for a balanced diet, and exercise, with emphasis on the exercise, since it is exercise, any kind you prefer, that will keep your metabolism healthy. It is easy, in this day and age, to enter a declining spiral in which one loses muscle mass due to lack of activity, which makes it harder to burn calories; your 'fat burning furnace' has become a candle, in effect.