Then I use my hands and try to explain the internals of the lock and show them what the pins are doing, or SHOULD be doing. The look changes and they furrow their brow and start "thinking" through the process, and staring AT the lock now instead of the tools.
I let them struggle for a while...

"Frustration leads to Breakthrough...., I once heard. That is, if you don't quit.

And THEN once they kinda have a grasp, and are gaining some confidence, I pull out either a cutaway lock, or an acrylic see-through lock. I do a quick 10 second intro again of the internals and their eyes go wide and they start to crystallize the process!!! Usually at that point they are able to get through their previous plateaus, they are hooked. They start to truly exercise the skill set of visualizing!
Not an expensive tool, but it suuuure pays dividends on your understanding! Much more effective than an info graphic or an online gif, not that those done have their place, but holding it in your hand and being able to truly play and experiment is priceless!
Hope this helps!
-OracleTac