Hard to do that with the loose parts of a disassembled shotgun... Or even a bolt from a rifle...
The point is that I wouldn't disable a firearm I might want/need, but for storage I'd sooner disable by locking
externally or stripping before locking internally.
I suppose I also see unlocking a firearm following a mechanical failure of the lock to be less credible than a mechanical failure of the rest of the gun. I know that we prepare based on the stakes, not the odds ... but I can't plan on that until I carry a kit of spare parts with each gun.
What works for me:
If you worry about the internal lock failing - carry a BUG or avoid the internal lock.
If you might need a firearm in a hurry - lock it in a obvious way (trigger lock or secure container) or keep it under control.
If you must internally lock a firearm, don't expect it to be operable without a full function check.
Now, I don't have kids poking curious fingers around, and I think internal locks are silly and useless, as they are an attempt to bypass basic firearms safety. Your opinion may vary, but
I think that safe firearms ownership was possible before anyone thought to add internal locks, and is possible without them.