I stopped putting anything on my fretboards and strings a long time ago. They only thing I do to my neck,
with the strings attached, is frequently bathe the entire length in shower to shower powder. I rub it with a clean dry cotton cloth. It is pure bliss!
My action is silky smooth fast with no oily, greasy, string dulling residue. It absorbs all acid, salt, grease, beer, or any other funk. Since I have been doing this my strings do not tarnish and last a long time. Any thing you put on your strings, even a damp cloth, gets inside the windings and clogs and corrodes them. I have studied this effect for years and I am convinced. Try wiping your strings with any king of liquid and they will be dull after. I dont think fretboards need anything but to be polished by your
fingers.
Victory Pete