You have items in your house that clean themselves, and you probably didn't even know it. What are they?

The Oligodynamic Effect was discovered by Swiss botanist, Karl Wilhelm von Nageli in 1893. He discovered that there is a toxic effect in metal ions that kills microorganisms or bacteria. It is still unknown how exactly these metals kill the bacteria, but these are metals that can be found in the every day items that you use around the house. For example, jewelry, silverware, and even doorknobs are considered self-sanitizing.

Although this toxic effect can eliminate bacteria, that does not mean that it can kill viruses. Since viruses technically aren't considered active when they are not in range of the host it is feeding off, they won't be able to live on the metal ions anyway.

Before you throw out all your cleaning products and stop washing all your forks, you should know that not all metals are affected by the Oligodynamic Effect. For instance, when it comes to germ-filled doorknobs, just because it is metal, do not assume that it must be clean. Brass doorknobs are capable of self-sanitizing themselves in about eight hours. If the doorknob is made of stainless steel or aluminum then the Oligodynamic Effect does not apply and those doorknobs will remain bacteria-infested.

(Source)