Unfortunately, if one were to invest a single gram of plutonium, not only are you ill equipped to actually properly harness even a small percentage of the heat energy it will produce, it also qualifies as a heavy metal, so there is every probability that whatever you do actually ingest before the chunk of plutonium exits your rear end, will end up in your bones thereby irradiating you further than the original gram of plutonium irradiated you as it passed through your digestive tract, mostly unobstructed, provided one doesn’t have a previous bowel obstruction.