Improvised and modified instruments are part of any self-respecting weird music creator’s repertoire. As for using plants (and banaynays) as conductive channel for a theremin-like instrument, it’s been done before (by Simian) but not on video, I think.
The sounds created are… shall we say, limited, but could be useful in a track, and are certainly fun to create. I’d try it with a succulent. I try everything with a succulent.