In this experiment we see that a golf ball is denser than detergent (it is also denser than pure water incidentally, which is why water hazards are so effective at ruining a golfer's day on the course). But, a golf ball is less dense than a saturated salt solution. Now the question is: if you pour the detergent on top of the golf ball in the salt solution, what will happen to the golf ball?
Special thanks to Duane Merrell for the idea, which I saw demonstrated at BYU back in February. Thanks to Emil Malmsten for excellent filming, and his Stockholm colleagues who were game to have a chat to me about this experiment.