[curt.clifton]

Originally Posted by MichaelShapiro

Weird. I went to Context mode, changed the filter to only display Completed, selected an Action, then Select All, and then hit delete. A lot of actions went away, but a few remained. I repeated the process, then got the same result. It took three or four deletes to clear everything out.

All that said, despite the quirkiness, this seems to work as a stopgap solution. But lots of productivity applications have a "clean up" function, and I think OmniFocus would benefit here as well.

Suppose your deletion caused all the child actions of an action group to be deleted. Then that action group suddenly becomes a completed action and will show up in context mode. If you have action groups inside action groups, this process can be repeated multiple times.

Think of your action groups like a shrubbery. The completed actions are at the ends of the branches. When you trim them off, you can see the next level of branches to trim. It might take a few passes with the pruning shears to chop that shrubbery off to the roots. (Or, for the Monty Python fans, you could just use a herring.)