It should also eliminate any problems with rust developing as I've heard can happen if people don't dry them carefully after using with water. Canola oil is a good substitute for petroleum based oils if you are going to use your knife to cut foods. It is not harmful, unlike petroleums and synthetics. There is also a product called Ballistol which is supposed to be harmless for food preparation areas. I tried olive oil but it dried out on me and gummed up the knife.
Canola oil seems to stay thin.
Soap and water will clean it out if it does thicken up over time. Mark the edge of the knife with an black indelible magic marker before starting the sharpening process. The marker comes off on the areas that touch the stone, so you can check to determine how consistant you are in holding the angle constant and if all of the edge is being sharpened to the same degree. You can reapply the marker during the process to continue checking. Oil will remove the marker when you have finished.