can'? - Well, you are referring to only small aspect of the issue - "maintenance", this is not necessarily the core issue! Yes maintenance is important - but then you are going down the route of questions like, How often is required to make it [safety catch mechanism] "safe"? Every day, week, month, year? Would it make a huge difference? Is there evidence that proves this? Can you honestly answer this?
You might actually find that it is also the "grime" and "dirt" that builds up in the recess that is also to blame (which may cause the safety not to engage fully!) - and this is not resolved by simply spraying loads of
in the catch mechanism! It's back to how it's been designed...
The actual issue is why is there a possibility that the safety catch is "not engaged" in all instances. If there is a chance that it doesn't engage - it's not "safe". A safety catch should be designed to be reliable, efficient and more importantly - "safe".
Notice my choice of works - "design" and "safe" - currently, this is not the case!