Years ago when I worked behind the gun counter at a large outdoor my standard practice was to cycle the action on any firearm they wanted to see, making sure it was unloaded and safe. My favorite folks (and there weren't very many that did this), would take the firearm from me, cycle the action themselves to make sure it was safe, and when returned tome I did it again. Occasionally we would just grin at eatch other, both knowing we could hapily shoot next to each other on a firing line without issues. I had a customer one time who was looking for a holster, yep we have them, here is one, they pulled out a concealed firearm (way before ccw permits were common), I pulled back the holster and explained that I would clear the pistol before she started showing it into a holster in the store. When I did a live round popped out of the chamber. However I will say that we seem to only remember the bad ones, the basic, safe, customers who handle firearms with respect seem to fade out of our memory. I always kept a cleaning cloth hanging out of my back pocket to wipe off any fingerprints with, I fully expected someone to touch any part of the firearm they needed/wanted to.