[sdiy] Frequency shifted from BBD?

[Didier Leplae]

I recently re-read the section in Barry Klein’s Electronic Music Circuits on bucket brigade devices and noticed a brief mention of using them as a frequency shifter by modulating with a ramp wave.
He acknowledges that there will always be an audible glitch and some noise issues. 
I experimented with this idea a little to minimal success, but curious if anyone else has tried this or seen it used in interesting ways.