It's not recommended, in case there's aluminum in the pot. Aluminum can react with some of the chemicals used in photochemistry.
Scientific supply stores sell large mixing jugs. I picked up a 5-litre one. It's very well made, and will last a lifetime unless I drop it while full of solution (and perhaps even then). Not cheap, however. Some use plastic mop pails, which work alright if you can carefully measure the appropriate amounts of water and draw lines at the water line, but because few are transparent, they are a little annoying to use. The price is right if you object to the price of the scientific mixing jars, though.