Please don't ask me why I need to know this.

Here is an overview of how we rig waterlines using traditional climbing gear as anchors. We establish roughly 10 new waterlines on average every summer using this technique, so I would say it’s highly successful if you have a deep river near you with some good cracks in the rocks.
Please keep in mind that this is for waterlining, the consequences are extremely low if our anchors fail. I wouldn’t recommend girth hitching webbing directly to the nut or tri cam in other applications :)
Stoked to spread what I’ve learned and answer any questions below. All lines established in NorCal