This is not an XXL version of one of my ceramic mate gourds, Fluff. But I applied the same glaze and technique to a mid-sized vase, and single fired it.
When working for single fire, you glaze greenware (unfired pottery) directly, and fire it in the kiln only once. This archaic way of working saves time and money, and it has a special appeal.
My high-fired vessels are completely sealed and dishwasher safe, they absorb virtually no water.