A couple of long soaks in hot soapy water (changing out the water in between) should do it, I wouldn't be particularly concerned about it though. If it's in the joints then it isn't very likely to make it onto food you're cutting, and a lot of the time it's probably Vic's own copious oil job from the factory.
The Spartan I'm using in the Spartan challenge I've owned for about a decade or so, but there's still Vic oil on some of the tools!