Hello from Ohio....
It's been a long time since I have seen a "Gun Clearing Station" at ANY gun store.
I remember years ago, the the gun store(s) I went to had a "Gun Clearing Station" right outside the front door with signage similar to this... "PLEASE CLEAR ANY WEAPONS YOU NEED TO PURCHASE ACCESSORIES FOR" All others should remain in their holsters while inside the building.
These station were usually a 50 gal barrel, filled about 3/4 full of sand and set on a wooden stand which made the barrel angel slightly so you could easiley insert the firearm and dry fire it after first removing the ammo. Of course there was a hole cut in the top to insert the firearm.
Seems like common sense to have one, but then again I don't own a business that sells firearms.
The "barrel o' sand" was adopted from military practice, and while it's so-so as a field expedient clearing station, it's not all that safe. Since it's only partially full of sand, a gun stuck into the opening at any angle other than 90 degrees risks either too little sand, or missing the sand completely and firing right through the side of the barrel.
There are better modern solutions. For handguns, I would use an "academy pad", like this:
http://www.safedirection.com/academypad.html
If I owned a gun store or sold at gun shows,
every handgun that passed from the case to the customer or vice versa, would be cleared over such a pad. You don't have to buy them new; you could make your own by buying body armor (perhaps past its usage date), cutting it down to pad size, and still be safe by doubling or tripling the thickness.
For long guns, there are also multiple solutions. Some of them are only good for a single discharge. While we hope to never have even a single discharge, ruining your clearing station just might end your operations for the day. There are other options, like this one:
http://www.snailtraps.com/checkitMini.php
Snail Traps work well for indoor range systems; this product is just a tabletop version of the same design. The animated .gif at the top of the page shows how it works. It's not harmed by a discharge.
Okay, all that said, 25+ years of combined military and LE experience have persuaded me that focusing on the "clearing station experience" often misses the point. It misses the goal of safely clearing a firearm after use, and focuses on rote clearing drills that seldom involve actually checking for ammo in the chamber.
The military range traditions of "Ready on the right? Ready on the left?" and "No brass, no ammo!" teach people to be little robots on the range, not sentient beings actually
thinking about gun safety.