Before spraying the oil, disconnect the fuel feed line as suggested to ensure that no additional fuel siphons into the engine, then connect the booster and start the engine as if running off a prime. This should remove ALL raw fuel in the engine. You can then squirt some after run oil into the engine if you are going to put it away for an extended period of time (longer than a few days).

Needless to say, remove all the rust with a wet Brillo pad or Scothbrite ... something that won't cause a lot of wear. Run the engine rich a bit to remove any microscopic residue. Remember, rust is iron oxide...a lapping compound.

Good luck.

George