HI!
I'm not sure if you are looking for subtle changes over longer times, or really fast stuttering?
I would try adding random control to the amplitude parameter of the sample cloud sound with smooth, so that the transitions are smoothed. I'm not at my Kyma, so I can't use the program to look for examples, but if you put a chopper-sound in to the amplitude parameter you'll get a "tremolo" style Amplitude modulation to start with.
So maybe you could think of it as amplitude modulation, Kyma can do it in various ways that could be considered as "jitter".