Guys you really dont need to be rubbing anything into rosewood fretboards, they have their own oils.
Cosmetically they might look better, but thats it, a bit of virgin olive oil maybe x2 a year is all you need, i have some pure lemon oil that i have used for over 20yrs
Naphta (lighter fluid) for loosening the dirt. Then 0000 steel wool across all the fingerboard. Finally, clean the board, polish the frets (mask the fingerboard and use the 0000 steel wool). When the frets are clean you can then pure lemon oil the board, its pretty simple really.