Is It Possible to Slow the Spin of a Black Hole Down?

The Penrose process is a way of extracting energy from spinning black holes by slowing down their spin. Simon Carter says, I was relistening to your Christmas message from a few years ago titled The Screwy Universe. You mentioned an experiment had confirmed this to Two Sigma and you were waiting to see if further details would either rule it out or further confirm. Has there been any further update over the last few years? There have been updates, but they're very slow and tentative.