I thought the same too at first glance, but by the 2nd looks of it, this area and equipment hasn't been used in a wicked loooong time. they originally prob put some kind of sellable bag over the ends, between each shots of coarse.

But this stuff here looks so old, rusty and dusty. I'm guessing that's why they aren't eating any.. kettles were probably full of decades worth of rust, bug shells and spiders eggs.

These guys look like they lucked out somehow to get access to this creepy basement stuff. before it was eventually pulled out? Maybe demo crew? got em all running and shot em a bunch rapid fire line style for fun.. over that easy to clean tarped up spot in front of it.