Metal Pickle Pot

[cheal]

I follow a number of jewellers on Instagram and keep seeing people using a small metal pot to hold their pickle. They heat it up with their torch on the side (as pictured). I've never seen or heard of these but think it could suit me a lot better as I am a hobbyist and my slow cooker takes an awfully long time to heat up appropriately. For one piece every week or so its really inefficient.

Can anyone tell me where I could get one or what to look for? I assume it couldnt be steel as that would spoil the pickle but would other metals be okay? aluminium perhaps?

Thanks