What is the drano test? How does it work and why?

A myth . This is a nonsensical myth where you mix drano and urine to predict the baby's gender. It is a myth and is kind of gross.
A test for the sex. First, it doesn't work. But for the curious: you mix your urine and drano in a cup. Wait 10 seconds and if it turns a darker brown, theoretically it is a boy. If there is no color change, you are having a girl. Unfortunately, not true.