It was once explained to me that WD-40 and other similar sprays were not lubricants as such. These sprays were considered as emulsifiers to break up and move old oil and grease away from the part to free it up. Why would you want to put something on a machine that will move the oil away from a critical joint. I suppose if you had a part that was glued in place by old grease or varnished oil you could put a drop in the frozen part to free it up. This drop would come in the form of being placed with an eyedropper from a can and not a spray. Just my opinion.