How often should grease or oil be added to the lock cylinder when lubricating locks?

In the context of maintaining lock cylinders, the correct approach is to refrain from applying grease or oil altogether. Many locks are designed to operate optimally without the use of lubricants, as adding grease or oil can attract dust, dirt, and other debris that may lead to malfunction or increased wear over time. In fact, most contemporary locks are manufactured with internal mechanisms that are intended to be self-lubricating or already possess sufficient lubrication at the time of production.

Regular lubrication in the form of grease or oil could compromise the integrity of the lock's components and may lead to decreased functionality. Therefore, maintaining a clean and dry lock is usually the best practice, which is why no lubrication is advised. This principle applies particularly to locks that are used frequently or are exposed to varying environmental conditions, where the introduction of lubricants can create more problems than they solve.