about the late reply. When I got the watch, I did some research on accelerating the development of the patina as well as cleaning the watch without damaging it. I read a few articles, ranging from hardcore chemistry to everyday household tips. In one of the household tips articles, I read about lemon juice and ketchup, and I confirmed it on one of the Panerai forums. I figured it would be harmless to try, and I did not have any lemons!LOL!