Basically a fancy name for "dishwasher". My ex felt inferior to some of his friends who had cool-sounding jobs, so I made this one up to make him laugh and feel better :)
JOE: Hey Bob, what are you doing with yourself these days?
BOB: Oh, hey Joe. I'm the assistant to the vice president of sales. How about you?
JOE: I'm an underwater porcelain technician.