Rope and Peg-Board Climbing
Rope climbing without using your feet and peg board climbing share the throne as the king of upper-body pulling exercises. I use these as advanced pull-up applications because they require a tremendous amount of extra body tension and add an increased grip strength challenge.
We used to only see peg boards in wrestling gyms, but CrossFit as helped to re-popularize them in recent years.
Note: Instead of going hole by hole or skipping one hole at time, I skipped several holes each time. However, in order to make these big moves, I used my right arm each time to create the power while using my left arm to reach. This is because I partially tore my left biceps in a bouldering competition years back, which prevents me from making big throws off my left arm.
In regards to rope climbs, I know many trainers and coaches don't use rope climbs for safety reasons. That's certainly a very legitimate concern, but to maximize safety, we have people begin from a sit start, and instead of climbing 16 feet up and 16 feet down, we have them climb up 8 feet, go back down, and do it again.
This allowed us to create the same training stimulus without ever allowing the athlete to climb to a height he couldn't safely drop from.