If you can control the reflection and/or specularity of the flake portion of the combiner, you could probably get a good sparkle from that.
In my bump map version, you can. the "sharpness" on the Glossy shader affects how quickly a glint goes on and off, and "Specular Intensity" controls the brightness. So a pretty fair spectrum of effects could be had with this technique.
In the original at the top, the bright spots are always bright from any angle so they didn't "glitter".