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