I read the question How do you remove garlic smells from your fingers? on Seasoned Advice and it reminded my of a claim I was always skeptical about. The accepted answer states:
The smell of garlic is due to sulfur compounds. When you rub your hands against stainless steel, the iron of the stainless steel will react with some small volume of those compounds, but much more will remain in your hands.
I have often heard the claim that rubbing the hands on a steel block really works but I wonder if there is any real evidence for or against this.