Funny you say those two - I’m using both currently!!My last school we used an old stainless washing machine drum. it burned very clean with no smoke. But, it does burn wood fast as it's mega efficient at drawing in oxygen. The lip around the top edge was perfect for setting on potatoes in tin foil. When the skips were still shut last May I got an ex display garden incinerator bin from Wickes. It is basically a big kelly kettle and without the lid on it burns clean and you can still feed it.