The difficult part of a video is often one sentence, not the entire clip. A sentence loop lets you repeat that line without manually dragging the timeline.
Repeat with a purpose
Each replay should answer a question: Can you hear the syllables? Where are the word boundaries? Which tone movement is unclear? Can you follow the rhythm when shadowing?
Once the sentence is clear and comfortable, move on. The goal is focused feedback, not repetition for its own sake.