[patkeefe]

I guess, in theory, the rings, especially the top ring, is mostly dry of oil during normal operation. The lowest ring in the cylinder, the oil scraper ring (oil control ring), is there to basically scrape the excess oil from the cylinder walls. So, providing the oil ring is doing its job, there will be little oil hitting the middle compression ring, and the top ring is essentially dry. During operation, oil travels from the crankcase to the combustion chamber, if it makes it to the combustion chamber (mostly, it does not). If you fog (essentially spray a cloud of oil into the chamber via the spark plug hole), you are going opposite of the direction of normal operation. So, you are putting oil where it usually isn't. Also, your cylinders are either Nikasil or Alusil, two materials that don't rust.

Some people swear by this fogging. Some people think it is at best overkill, and at worst, useless. Choice is yours. I can say most wear in an engine is during start-up, which is why Accusump is so popular. So, really the best thing to do is pressurize your oil system prior to turning the key.