Community Tip - Did you get an answer that solved your problem? Please mark it as an Accepted Solution so others with the same problem can find the answer easily.
X
I can't look this up now, but I think you can extend whatever the ootb taskcompleteprocessor is and clear out the activity comments there. From the workitem, you can get the actiivity/activitytemplate/process/processtemplate/etc, and clear the comments if your criteria is met.
