Hmm.
I honestly have only seen 1 Ibanez with a Maple fretboard before, and that was a JEM 777. In any case considering that Maple fretboards would be finished i.e. coated with lacquer, I would assume that by using normal guitar finish cleaners would help.
And of course, as mentioned above, the usage of Lemon-oil would be, well, disastrous. Maple is pretty much a soft wood, and it soaks up moisture easily, hence the need for Maple necks to be finished, no matter how thinly. Applying an oil-based substance onto your maple fretboard would surely be unadvisable.