After many years in the abrasive industry specialising in wood, marble, stainless steel and the automotive polishing industry. I have accumulated a lot of experience in what works and what does not when making a superior product. 
I give you my newest addition to guitar care, the Merko LO12CW . An ointment specializing in guitar fingerboards. Based on wax and the union of certain oils, without the use of chemicals and silicone. Won’t harm your precious instrument or the environment. 
It would last you approximately about 4 years!!!
Please message me if you want to see it a video.