Personally I do not trust anything not made specifically for cooking in to cook in. Many metal water bottles especially the cheaper ones have Liners sprayed into them which is common for almost anything metal these days including food and beverage cans. The best lightest weight pot I have found while not romantic or top tech is the little one withen most inexpensive messkits. I can easily remove it and take just that along with other gear in a "lightweight" assortment for camping.