I have one here It is a review of military surplus one. It cost $3 in bolivia. I didn't find it super efficient.

A better idea would be something like an old can with holes for venting.

I know people aren't huge fans of the swiss ranger setup, but I'm planning on trying it out this summer with esbit as the old solid fuel tablets i got here were fairly efficient with it.
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Without a doubt, the hardest thing of all in a survival situation is to cook without the benefit of seasonings and flavourings. - Ray Mears

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