Of all the stones, Granite is the least porous. ...Water left on a Granite countertop for a long period of time will show evidence of moisture. It will however evaporate and the "dark spot" will disappear. Oil left on a Granite surface will slowly be absorbed into the stone. It is recommended that any spills be wiped up when they occur. I read on the web that "If the spill is not caught in time and a stain does occur, a poultice may be applied to draw the oil back out of the stone. Over time the oil will naturally redistribute itself in the stone until it becomes virtually undetectable." I myself am trying a heavy poultice of baking soda left on for 24 hours.
There also is a product called StoneTech Oil Stain Remover. Does anyone have experience with this on countertop veg oil stain?