I've been carrying a pocket knife every day for over 25 years now. Never had to resort to scrub brushes and solvents. A toothpick works great, the wood fibers crush down into those little slots and gets it all out. Lightly oil just the pivot pins. Work the blade back and forth a couple of times to get the oil in and then try to wipe the oil off. Wipe it good, you're not going to get it out of the pivot, and any extra will just be a dirt magnet. For the oil, I really like a synthetic, high viscosity, extreme pressure rated bicycle chain oil. The bicycle racing community is not going to risk their equipment or a race using cheap oil, this is good stuff!