I will suggest you make your own home make coconut oil just like I did for my ward and it worked.Buy 2 or 3 coconut break it,cut in bits and blend in your blender add hot water and leave in fridge for 24 hours till the following day rake the hard white oil on it and heat your frying pan to fry out the original coconut oil.use on him "consistently" and look out for effective result.
Native chalk is white. You need to break from it, ground it and mix with water to make a paste. Heat it in fire with clay pot or steel. When it is warm, mix it with white capsule and apply to the affected area.