baking soda rockets

Yesterday afternoon, M decided he wanted to do some science experiments. OK, first he tried blowing a bubble within a bubble. It seemed to work somewhat, but not great. Then he wanted to try rockets. We don't have any Alka-Seltzer, so we decided to try baking soda rockets. We found a water bottle and a cork and took them and baking soda and vinegar outside. First M added the baking soda and vinegar to the bottle.

Then he corked it, shook it a bit and put it upside down in a brick.

Then you wait. And wait some more.

Then, maybe it needs to be shaken again? Oops, it exploded all over M.