deleting Drawing Substiution keys/

How do I delete the little hash marks created when I slide the Drawing substitution slider? For instance, I animated some lip sync on a character’s mouth but now I want to redo it and start over. How do I delete the ‘keys’? I tried just hitting delete but that does not work. Any help would be greatly appreciated!

Do you want to redo the drawings on the mouth shapes, or redo the synching?

If you want to redo the synching, then you can just select the exposure in the timeline and hit delete. Or you can select the cells in the Timeline or the XSheet and hit Z, for Clear Exposure and Pull, which will remove the exposure and pull everthing ahead back to the current frame.

If you want to redo the drawings themselves, then you can simply select one of the drawings and start editing it, and it will update wherever it’s used in the timeline.