Is there a decided best way of dealing with this? My primary problem seems to be the front edge of the laptop in front of the trackpad, since I commonly rest my thumb there, but of course, anywhere I touch it consistently will have some level of this problem. The last one I sold, the guy emailed me and asked if I spilled acid on it or something. (I took closeup photographs of it in the listing, but he was just curious how I could have done that.) I assume it's bacteriological. I tried wiping the places down with alcohol daily when I noticed it starting, but it didn't do anything to slow it down. My replacement MBP 2016 (that decided to not charge or turn on anymore after a couple weeks of use) will be arriving soon, and I'd like to get a head start on the pitting problem if I can.