My outboards big and small were always oil fogged at the end of the season. I have a few 20,30 year old small outboards that are well used and have never had the engines apart for any problems. The only precautions were the oil fogging at the end of the season.
When I got into gas powered models some of my first were Quadra engines. I oil fogged these same as the outboards and they still run today with no problems. A couple of carb rebuilds again no problems with the old carb castings.
I just bring the rpm up to a fast idle no more than 1/4 throttle and spray the fogging oil down the carb until the engine stops. Done. Drain the tank. If your paranoid about the fuel in the carb take the top and bottom plate off the carb and drain and let the gas evaporate from the carb. Replace the top and bottom and its ready for storage.
Dennis