On my cheapo guitars i use beeswax polish and/or wire wool - note these are all rose-wood boards, polish CAN can dry out necks [according to it's formulation,etc] so i won't use it on my more expensive guitars. Maple boards tend to be sealed and most guitar companies recommend they are only scraped clean of gunk. I have also used linseed oil to clean/treat rosewood boards and this is what Gibson recommend. Have a look at Fender's website to see what they say about cleaning your fretboard and follow the official line then you have the least danger of any wood damage.
Accuracy,you say? hmm interesting concept..