Can someone with a Dirty 100 or who knows about them tell me about the rosewood fretboard on them? I scored #91 last week. The fretboard is not only stunningly beautiful, but it is like a tight gloss impenetrable/non-porous finish. I changed strings on the guitar last night and proceeded to put some Fret Doctor on there, but it would not even penetrate the wood, just sat on top until I wiped it off.