Smoker

Check with oil suppliers, they may have new unused drums that you could buy.

Burning out drums? You can do that?

If you use oil drums, the remailing oil will burn off easily. I wouldn't try it with other chemicals though.

Some food processors use the metal 55 gal. drums for food shipping. They generally use a heavy plastic bag type liner so the product never touches the barrel itself. My family uses them to pack IQF strawberries for rail car shipments, Spice makers use them as well. They are essentially a clean metal barrel w/ no contaminants what so ever.
Hope this helps & good luck!