There are many types of retainers used today. Some are removable and some are bonded in to the back of the teeth. You must be careful when handling your retainer as they are fragile and sometimes costly to replace. When the retainer is not being worn store them in the retainer case that is provided to you.
Cleaning your retainer all that is needed is your toothbrush and toothpaste. Remember, boiling the retainers in hot water will cause the retainer to loose its shape and will not fit.