If you think about it then fret board is just a thin strip of hardwood that is glued down to the neck. But its is one of the most important parts of a guitar. It's the contact point between the body of the guitar and the notes to be played. The stabilizing bedrock that hold the frets is the body of the guitar. It's that part of the guitar that that is constantly being used and touched by the users so it is going to get dirty. Not just for the sake of aesthetics but also for the sake of hygiene the instrument that's being so frequently used by you must be cleaned regularly.

There are so many cons to leaving the guitar unclean for a longer period of time. The buildup due to the uncleaned surface of the fretboard can work it's way through the strings. When the strings get coated with such buildup, it will lead to hindrances in the guitar's sonic performance.It doesn't matter whether the frets are pressed into the pine neck or into the streaky and elegant ebony, it's better to clean the frets regularly for getting better productive practices to play guitar. 

Things required for cleaning 

Below is a list of crucial materials for fretboard cleaning and general guitar maintenance. Altogether, everything on this list can be acquired for less than $50. 

Here are a list of some of the must have products to clean the guitar thoroughly. 

• Regular soaps or cleaning detergents can be very harsh on the wood surface of the guitar. Soap that is potassium vegetable oil-based is very gentle on the wood. But every bit of the material must be cleaned away thoroughly or it can lead to even more buildup and form a crusty layer on the fretboard. Depending upon the brand of the soap the cleaning might require less or more time. 
• Guitar Polish: There are many different brands of polishes available in the market. Some of the popular brands are made up of various mineral oils and solvents. These are excellent to not only clean the filth but also leave behind an iridescent sheen behind after cleaning. Some brands even have specific smell to them not that it matters. But if you are sensitive to smell and dont want any lingering scent on your guitar then choose accordingly.
• Fretboard oil: Just like the polish any brand of oil can do. Many people use cuting board oil and their instrument is just fine as well. The main difference between a reputed and somewhat costlier oils is that of viscosity. Unless someone is working with vintage guitars any oil will do.
• Miscellaneous Items: There are also some random items that you might need to clean your guitar. These items can be easily available at home or any variety store. These are paper towels, final finish/super fine steel wool, microfiber cloth and a few fretboard guards as they easily get lost.

Maintaining the musical instrument is as important as creating music on it. Hence the right care and most importantly the right knowledge to right care is necessary to take care of this beautiful musical instrument.