Cooking in the dishwasher.
I thought the most dangerous thing about this one was messing with the warranty on our dishwasher. It turns out getting the kids to eat them was a lot harder than I imagined. We threw a couple of hot dogs in the top shelf loaded in four layers of tin foil. After the two hour cycle they looked fine. We talked about how the hot water in the washer was no different than boiling water on the stove. They thought it was cool until we figured out it would only take five minutes in the microwave or 15 minutes on the stove compared to 90 minutes in the dishwasher.