Hi Gary.
Its the build up of micro particles in the oil that causes the wear in clocks and watches, blowing air into the movement would not be of any benefit as whichever air source you used would just be taking more air from the atmosphere which is already contaminated. Even if you used compressed air in a can which had been loaded under lab conditions i.e a dust free environment this would not remove the particles which have already entered the oil during the six month period. You could always run a test with two identical clocks or watches, serviced to the same standard, blow one out and not the other and check again for wear after a couple of years but I dont think you would find much of a difference wear wise.
Paul.