Here’s a variant for people who can do a weighted pull-up with around 75% of bodyweight. Lightly assist with the other arm, primarily to avoid the swinging and rotation (which you can see still occurred on the right and led me to smash my recovering knee in the metal rail: https://www.instagram.com/p/BzA5Su7j7uB/).
I’ve found that once you can do 2-3, you can usually begin with an unaided eccentric version (climb up and lower yourself with only the one arm). Watch closely where my body is facing at the top and at the bottom of the movement. Keep this in mind, because even elite gymnasts and climbers don’t have the body facing the exact same direction at bottom and top of movement. It’s actually most natural to finish a one arm pull-up in a chin-up position.
As with most supramaximal training (doing eccentrics with a greater load than you can work concentrically), the rule tends to be work up to 3-5 clean reps in close succession before the concentric will occur. I’ve used this metric for standard pull-ups with hundreds of clients. Once they can lower themselves in a controlled fashion for 5 reps, they will automatically complete a full clean rep without being cued to do so.
You might’ve noticed that banded pull-ups never result in full pull-ups. Kipped muscle-ups don’t result in real muscle-ups. That’s because the full load is never even handled in the eccentric portion. At some point, you must encounter the tension which you want the body to produce.