the fogger just comes in an areosol can and is easier to apply in my opinion, but adding oil is also easy. The engine fogger is a flammable substance because it contains petroleum distillates and propane. The engine fogger is highly flammable so when starting up later you won't have the troubles like you would if the cylinders had oil in them. I think the fogger is a much effective application aswell, where as if you just put oil in the cyclinder and cranked it over you wouldn;t get all areas of the cyclinder. I bought Wynn's engine fogger u can find out tonnes of information in the Pdf. file through this link.


http://www.wynns.ca/pages/english/e_msds-con.html

either way i am sure both ways are effective if done properly. ( oil or fogger )