Basically, use a special powder spray for keys. However, if the powder spray does not restore smooth movement, apply a small amount of Bell Hammer to the key (do not spray directly into the keyhole) and repeat opening and closing the lock several times. When the key moves smoothly, wipe off the oil on the key.
If excess oil is left on the key or keyhole, it may cause the following problems
Dust and other substances will be absorbed by the excess oil, and impurities will be trapped in the keyhole.
2. The impurities will stick to the key and stain your clothes by touching it.
2. The impurities will stick to the key and stain your clothes.