Hey guys.
I just took the strings off my guitar because they were really really gross, and I thought this was the best time to clean my fretboard.
On both sides of any fret, there is all think gunk stuck to the fretboard and I want to get it off.

Could I use lemon juice, or any other liquid as a replacement for lemon oil?

Thats mainly jusy oils from your fingers. You could use just a rag and soap and see how much comes off, its actually pretty gross and makes a huge difference after you do that and oil it down.
Well, ive used simple green before and it took like everything off of it and it looked like new fretboard. Afterwards i just oiled it a little and it felt good as new. But if your skeptic just try a wet rag at first and just wipe the board off to see if you get some black stuff on the rag. If you do use some cleaner make sure its dry before you oil it again.
I'd say leave it, it shows that you actually play it!!!
Livin' Easy, Livin' Free
Rosewood fretboards are unfinished and not sealed. Don't use anything but lemon oil.
Hi, I'm Peter