I would start with hot water, regular dish soap and a brush. If that doesn't work, move up to something more abrasive.
You could also run it through the dishwasher. I recall Sal posting about running FRN handled knives through a couple of cycles. This was before Spyderco started using H1, so a Salt shouldn't have any problems. I would pull it out as soon as the cycle was finished and blow out the water though.
Bruceter