This wonderful musician doesn't play slack, but her music has elements of the slack style, e.g., percussive background to the melody.
About six minutes into the video she describes her guitar and how she adorns the strings to produce some amazing sounds. I think Sonny Chillingsworth would really like what she's doing.
The first song isn't so great to my ear, but the second is a fine instrumental, and the last just dazzles.
If you like avant garde guitar, you'll find this video a treat.