A substance that is immisiscible with water and that can be made cloudy
It smells but I think chloroxylenol 48 mg in 250 ml ethanol mixed with water would be what your looking for, I'm not sure what it's called where you are but it's a common antiseptic sold everywhere, in Australia the most common brand is Dettol. 

Also , if something is completely immiscible with water it will form two phases , both relatively clear, eg water/xylene. 

If you mix the solution it will go cloudy but then seperate, the longer it takes to do this depends on how much it was mixed, an emulsion can be formed but that's not what your looking for. 

You want something that's only very slightly or sparingly soluble but doesn't seperate into a different phases once it's mixed.

Dettol came straight into my mind but I'm sure there's many more. Arrowroot or cornflour mixed with water would produce a milky/cloudy solution.