I saw a large, 5-6gal, pot with a lid and spout at a farmer's market and thought about getting one for fermenting/aging like they used to back in the day.
My 2cents? Would the pot stand up to having boiling water added to it for sanitization, or would it crack? If you brought the temperature of the whole pot up to a certain degree, then even what has soaked in to the pores should be sanitized. People reuse oak barrels, and the brew works in and out of the wood, but the wood stands up to having boiling water added to it to sanitize. Then you have the issue of flavor contamination. Ceramic baking sheets are considered "seasoned" after a few batches of cookies, etc..., but you don't wash them cause the soap would soak in and leave bad flavors the next few uses. I imagine the same to be true if you did a big, full-bodied brew followed by a lighter brew. Though subtle, there may be off flavors or even off coloring in the subsequent batches.
Idk... I might try this now just to see what happens. The pot I was eyeballing had a rubber gasket on the lid, which was fairly robust. Not sure about the spout though. It was $100 and that is a lot to spend just to experiment. Please update the thread if you decide to try.