The smart straw is a long red tube that, in its undeployed state, remains snug against the WD-40 canister. If your WD-40 comes with a smart straw, snap it into place by pulling up on the gray base of the red tube. This base is located near the top of the WD-40 canister.
It can also help to tap the hinge pin up just slightly and spray the WD-40 in the gap on top of the hinge. This allows the spray to penetrate the inside of the hinge and the pin.
You can also use a paper towel sprayed with all-purpose cleaner. If you lifted up the hinge pin, remember to tap it back down when you finish spraying.
For a more precise spray, look at the area in the door jamb where the hinges are located. Close the door and take note of any area where metal contacts metal as the door moves. These are the areas you’ll spray. You should also spray the door latch mechanism.
If you have access to two door hinges, be sure to coat them both.
You can buy 3-in-1 oil at a hardware or home supply store.
You can wear rubber gloves during this process if you don’t want to get wax on your hands.
