I use the GSH string care system every day (when I remember!!!!) and never have a problem. I think the GSH system is for strings and not really intended for the fret board ! I am careful to change strings after about 40 hours of playing them (they star look burnt and the tone goes)or every month, which ever is the sooner ! Im using Lemon oil on the dark wood fretbord every other month and it is fantastic, I give the fretboard a once over with a cloth, make sure I dont put on too much oil and work it in. Works a treat here in the ever changing climate of Iowa !