This shit rocks.
My RFR I just got was dirty like the top portion of the picture all the way down the neck.
It picked up all this crap off those first two frets
This was what it used across the whole neck. Granted this thing was dirty as I've ever seen.
It is a bit pricey, but it really does the job.
I've always used something like Flitz's or Mothers polish on my frets with a microfiber towel, I don't think I'd think about using that stuff on wood. I guess you used that Gorgomyte stuff on the back of the neck with success? That is a benefit I would suppose. A tube of flitz's goes a LONG way when it comes to shining up frets. I need to try this stuff out I suppose so I can do the pepsi challenge.