Exercise cannot tighten your loose skin, but you can minimize the amount of loose skin you have. If you have excess skin, patience is key as you wait for your skin to adjust to your new size.
A Pepsi takes between 30 and 45 minutes to freeze solid, depending on the temperature it was at before putting it in a typical home freezer. Be aware that most (but not all) Pepsi containers will burst if you keep them frozen for more than 2 hours.
The freezing rate of coke in a plastic bottle when placed in a freezer is about 20 minutes although it may need to be removed to allow the carbonization to be released before it becomes solid. This is also the same time for a diet coke in a freezer.