Hello, I've just become the proud owner of a Spyder 4 (number 18) after many years of coveting Alembics. I've always used Fast Fret prior to playing to whizz up and down my strings more quickly. Mindful of the instructions to only use pure lemon oil on the fretboard, I'm wondering whether it's still OK to use Fast Fret, as I would normally apply that to strings and fretboard.