I bought and used Gorgomyte before, though a famous luthiers' supplies mail order catalogue carries it in a package that does away with the famous strings brand.
This version supplied with the GHS brand has a different smell, still quite penetrating during the use, but a lot easier on my nose than the original one (because it lacks that coconut scent that turns my stomach).
Gorgomyte is to good effect a polishing cloth of mild abrasive capacity, imbibed with a sort of oil that transfers to fretboard during the frictioned swirl required to put it to practice. It works great on rosewood, on ebony, and probably pau-ferro, too, but the manufacturer clearly warns you on the box not to use it on maple fretboards. I treated a phenolic resin fretboard, too, somehow risking it (because it wasn't mentioned in the product directions of use); pheew, it came out exactly like... the frets it carried: mirror-shining!
Don't be fooled and think you can do a whole fretboard and all its frets in two minutes' time: you can't, simply, if you want your frets to shine anew. You'll need to patiently wipe each fret for minutes, one by one, and the wood surface between each two of them, again for minutes.
If you want shiny frets, like in mirror-shining, be prepared to wipe liberally and vigourously for a good 25 or 30 minutes (if a standard electric has been idling in the shop's racks for months, or inside its case under the bed for a year or so).
But, even if you muster all the patience it takes, even at 30 minutes' time you're still saving a huge amount of time and being lightning-fast, compared to using abrasive rubber-erasers for shiny frets, which require you to protect your whole woodwork of your fretboard by masking it with paper sticky-tape (minus the frets), which alone takes at least as much time (and the use of an ex-acto knife).
Word of wisdom has two applications, here: use protective gloves because the metal residue removed off the frets and mixed with the oily concotion stains any surface in a really effective (and black) way, your hands and nails included; and, for the very reason, if you're working an instrument with a delicate, clear or untreated neck, make sure to mask it off entirely, and protect it before wiping Gorgomyte on the fretboard.
I like Gorgomyte cloth better than lemon oil for treating dry (or very dry) rosewood fretboards, it seems to make it with a single application (when oil calls for two or three pass at it instead, which is more dangerous to frets stability).
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