I wear a gold chain every day to work because I need to wear a security badge.  Over time the oils on my neck discolor the top part of the chain.  I have tried scrubbing it with dish liquid and a toothbrush, but it doesn't restore the shine.  I read the good reviews on this machine and thought it might be a worthwhile investment.  I am happy to say that I was not disappointed.  I put the chain in the Optima cleaner and set the timer for the longest setting.  It came out looking like brand new.  I'm sold.