Much like any other equipment that you ever purchase, there is going to be a bit of maintenance involved with regulators. Now, it is nothing extensive and instead, you just need to occasionally clean and disinfect it when you start noticing your regulator needs it. Right off the bat, though, you need to know that when disinfecting it, avoid products that are not specially designed for dive equipment. Through your local dive shop or even via an online retailer is where you should be receiving cleaning products.
However, when it comes to cleaning scuba regulators all you really need to do is take a scrub brush with a detergent that contains no hydrocarbons to clean them out (including the mouthpiece). Locate any containments such as saliva, salt, seaweed, and mud and then rinse it thoroughly with fresh water.