If the oil used is a pure food-grade mineral oil, which is completely colorless and clear, it should clean up well with a liquid dish soap and warm or hot water. Other lubricating oils might not be completely colorless and might alter the look of clean, white material, rendering it yellowish or green. I realized a long time ago, this is how food-grade mineral oil easily cleans up from my hands, sharpening stones/hones and anything else. The main caveat being, if the oil is blackened by dirt or steel swarf, it'll be difficult sometimes to get that dark & dirty stuff carried in the oil out of porous material, even if the oil itself is largely removed from the material. If any dark, gritty particulate stuff gets embedded in the material, it's very difficult to remove it completely without doing something more extreme, like sanding down to clean material (I'd avoid that, most of the time).
So, with all that being said, the first thing I'd do is wash the knife in warm water with liquid dish soap, using a brush (old toothbrush) to do any scrubbing. Then rinse it all out with hot water, which evaporates quickly, making complete drying easier.
(Edit: I errantly wrote the above thinking about another thread concerning oil staining white bone - but the same could apply to micarta as well, for the most part.)