This is the sound of two plastic aspirin bottles being shaken. One bottle is large and the other one is very small. Each track got a pass through Audacity with the pitch lowered on the larger one and then a slight dose of gverb effect. The other one has the pitch raised a bit with an equal amount of gverb. Then I made one copy of each and tacked them on a second before the end of the first group in order to lengthen the clip a little bit.