For a quick way to remove oils from the surface of a swimming pool, throw in a tennis ball, suggests home decorating and design blog Shelterpop.
Photo by Nicholas.
The reason a tennis ball works for cleaning pools?
Its velvety surface will absorb the oils left behind on the surface of the water from visitors coming and going.
(Note: you can add a dog to help out, as in the photo above, but we're not sure if this would also negate the cleaning advantages.)
A Surprising Way to Clean a Pool [Shelterpop]