For the process to go quickly and easily, you need to make sure you have all of your supplies in one spot, so ideally, all you'll have to do is run a hot water tap. First, fill up your sink with hot water. Next, use a cleaning agent that is designed specifically for porcelain sinks. Place the agent into a spray bottle and spray the sink's surface down. Let it sit for at least 10 minutes, then use a sponge to scrub the sink's surface until it shines.