Yes, I used one or two flashes, triggered by radio remotes. All settings were on manual. Try different backgrounds and flash positions - one single flash is sufficient.
The really difficult part was the timing - getting the picture exactly when the drop hits the surface. Another advantage of working manually is the immediate reponse of the camera, with no pre-flashing whatsoever.
I created a simple device (a plastic bottle, cut in half, with a small hole in the cap and hung up face-down) which I filled with water. It keeps dropping constantly, which made it possible to shoot series of pictures, as long as I can hold the rhythm.
A simple 1.8/50 mm will work, a macro lens will even better.
Enjoy the experiements, the results are really amazing.