How can I clean guitar fretboard?

I have a fender blond wood guitar fretboard that has a green/grey stain from the guitar strings – I have tried various methods to clean the fretboard but nothing works – any suggestions?

the finest steel wool you can get, and take care or you’ll scratch the board. also plastic scrubbers

The String Cleaner ‘Guitar String Cleaner’ By ToneGear

Boss Gt-100 Effects Processor Recording Bundle w Mogami Cable, Strings, Guitar Cleaner $549.00 This package for the Boss GT-100 comes with HD, Gold Plated Mogami Cables as well as well as a cleaning kit to keep your instrument in top notch condition!…