I knew that one of you guys out there, had the answer. I use some of my knives on camping and fishing trips and sometimes they can really get trashed in the wilderness. I guess I would rather get my knives dirty using them as opposed to them collected dust in a dresser drawer.
You can clean them with pretty much anything and they'll be fine. No need to use a solvent, though. If warm, soapy water and a scrub brush, toothbrish, or sponge doesn't work, then sure, try some WD40.