WD 40 stinks! I would use food edible Mineral Oil instead.
3-in-1 (or sewing machine) oil works great.
Most people don't know that WD-40 is NOT a lubricant.
WD stands for Water Displacement.
It was originally made for older Distributor type automotive ignition systems. When things got damp or wet and the engine wouldn't start, WD-40 was used to spray inside and outside the distributor cap to displace any water or moisture that was causing the spark plug voltage to short to ground.