So I had a new Dovo that I was using for a few months. After every shave, I would dry it off with a towel, and cover with mineral oil. Eventually, I would apply alcohol before then dry off, then apply the mineral oil. I found that when I did that once, a few days later I saw a huge brown streak on the razor like someone had smeared chocolate/rust colored stuff, but I couldn't get it to come off so I got rid of the razor and am now getting a new one. What happened and how can I prevent it from happening again?