Many companies use some form of this demonstration. Amsoil has just spent some money and come up with a really neat demonstration (at least I think it's neat). I happen to have what looks like an extremely large mouse trap that does the same thing, but you do take a risk of smashing your fingers if the darn thing slips while locking the mechanism. Some companies just use two hammers. The purpose of the demonstration is to show how said grease does not pound out, which happens under certain shock load applications, like the bucket pins on a backhoe. So I actually find this test interesting.
What you have to be careful with is what grease you test against. You better know what the competition offers. Every oil company out there has a grease that will work well with this demonstration. You just have to pick the ones that won't, which most people doing a demonstration like this will do. It would not make much since to use a competitors grease that would do the same thing.