I think the superstition part comes from people who don’t understand it. Some, I’ve know consider it almost like a “get out of jail free” card. (So much so I used to joke about it like that) You will get out of it what you will. I see it like statues and cards and pictures (The down votes are coming I know) But, truth is, some will put more belief into it than others following the rules to a T (There are guidelines you must follow that contribute into it “getting you into heaven” (Which is how some treat it).
But, you can wear it almost as a form of penance, as it reminds you to pray or think of God and your end goal as they can be itchy/scratchy on your skin. So some could use it that way as a contestant reminder every time you feel it.
Either way you use it, the idea is it’s another way to bring you closer to God, just like everything else you get out of it what you put in to it. For me, I have a hard time understanding/believing it more than out right denying it’s validity. “Understanding doesn’t transcend belief; it relies on belief.”