Y'know, I really suspect that those ovens really only did make pots. And took care of trespassers, of course. Trespassers will not be prosecuted; they shall be cooked alive.
My youngest son used to take pottery classes. The ovens/kilns that the art studio had were not nearly so huge. The "artist" in me kinda cringes to think that pottery would be so mass produced, but I suppose it had to happen.
LOL, I am sure they did. My imagination occasionally kicks in and in the 19th century employment in factories was no fun at all.