With vertical cylinders: You can use a teaspoon or two of motor oil. Then crank it over a few times to spread the oil around. Then reinstall the plug.I can try this, how do you squirt oil , how much using what?
With horizontal or tilted cylinders: Get a foamy or fogging spray made for storing engines. Spray around inside to coat all the cylinder walls, then crank it and reinstall the plug.
I've found that if the engine is stored inside a wood-framed shed or garage, this isn't really necessary. The wood frame tends to keep the moisture at bay over the winter.
Items stored inside a metal or brick/cinder block shed or garage, or with a dirt floor, will have condensation and rust all over anything/everything metal. This is when preventative measures are absolutely necessary.