Mask off the parts surrounding the damaged areas, to protect them from de-anodizing treatments, by covering them with nonreactive plastic. Tape the plastic securely at the edges to prevent sodium hydroxide from seeping through to undamaged parts of the body.
Pour a small amount of sodium hydroxide onto a piece of laboratory cleaning tissue. Use the tissue to remove the damaged metal oxide coating from the actuator surface, revealing the base metal. Laboratory cleaning tissue will not deposit fibers on the actuator surface, nor will it abrade the surface. Use the distilled water squirt bottle to deliver copious amounts of water to the actuator surface, rapidly flushing away the sodium hydroxide.
Paint over the base metal, using a metallic paint with a finish similar to the surrounding anodized surface finish.
Remove surface metal oxide coating with laboratory cleaning tissue saturated with sodium hydroxide, as described above. Use distilled water in a squirt bottle to flush the sodium hydroxide from the actuator surface.
Sand the base metal with sandpaper until its surface is relatively smooth and even to the touch.
Paint over the repaired base metal, using metallic paint with a finish similar to the surface finish of the rest of the actuator body.