Welcome Haitham,
"Also reaches into the areas between fingerboard and fret"
Sounds like they want you to work it in well. Force some under the fret wire with a
Q-Tip
"The oil can be added in small amounts directly to the fretboard using the nozzle. Immediately work it into the wood with a thin cloth or a small brush. Pay particular attention to the frets. High-quality care - Made in Germany!"
Mike Dulak uses Howard Feed And Wax.
Feed-N-Wax Wood Polish & Conditioner | Howard Products