I don't think there's much point to spraying fogging oil down the carb of any 4 stroke, it's regularly done on 2 stroke outboards or any other 2 stroke for that matter, because after going through the carb/s it will lubricate the entire engine, crank, bearings, rods, reeds, pistons, as well as combustion chamber, and it will stick to everything. A 4 stroke will just burn it right off, it's not going to lubricate much, being as the oil is what lubricates a 4 stroke.
It may do a little good to the combustion chamber by being sprayed into the spark plug holes, and then turning the engine a little, but even that's probably more trouble than it's worth.