Well, I’ve needed to clean the fretboard on my guitar for quite a while now and have been putting it off for a little over two years. I searched around the net, and the most common answer I could find was to use some really fine grade steel wool. I went out and purchased some and gave it a go, and it really sucked. It kinda worked, but only if I really put some elbow grease into it. Thinking that there had to be another way, my wife looked at it and said “hold on, let me try something…” She then came back with a Mr. Clean Magic Eraser and proceeded to attack the fretboard with great determination. About 10 minutes later, the fretboard looked brand new! Naturally, I was very impressed with the results. Please note, do not use any water with the Eraser, use it dry. Then follow it up with some Old English
Malt Liquor Lemon Oil, and you are good to go.
PS. My guitar is a Carvin and kicks ass!