Nay, for me.
First of all, it won't do anything for your fingerboard. It is supposed to "lubricate" your strings, but I never liked the feel of it.
If you want to clean your (rosewood or ebony) fingerboard, then get some OOOO steel wool (good quality oil free stuff, which you probably can't find at your local hardware - try a good woodworkers store like Rockler or Woodcraft). Use the steel wool to clean the board, and then get some mineral oil or lemon oil to condition the fingerboard. You don't need to do this very often, maybe 2-3 times a year.
If you mean that the back of your neck is grimy, get some GHS guitar polish, put it on a clean lint free rag (old clean tee shirts with no printing on them are perfect), and use that to clean it up. It's probably going to take some elbow grease to get it clean if it is going all gummy on you. (The GHS polish is a bit more abrasive than some guitar polishes, so it is good for more serious cleaning.)
Light
"Cowards can never be moral."
M.K. Gandhi