I am in the habit to pour either trichlorethylene or ether in the "innards" of my rifle prior to going to Africa.
Especially in Burkina Faso, the sand is everywhere and in the air when the Harmatan wind is blowing.
It may result that the sand particles will agglomerate with the oil or the grease in the works, forming a paste that could jam the rifle or at least act as sandpaper and damage the mechanisms.
This decision is a two-edged sword : my rifle visited the Victoria falls and was rusted to the point that only the gunsmith managed to release the bolt.