Don't spray into the vent - everything will be covered in the spray lube and as it gets older and a little sticky all sorts of dirt will stick everywhere and create a real mess down the road. Wholesale spraying is not a good idea. My friendly TV tech had a customer that had a slipping belt in his VCR that was squealing - to save money he tried to fix it himself. He took the VCR apart and sprayed everything with cooking PAM spray to stop the squealing. Of course the VCR did not work at all - it ended up having to be scrapped as repair was too expensive. Moral of the story - Get to the fan and do one of the three suggestions - in other words - don't go for the easy shortcut.