Purging Used in Revit Template

Hello Dynamo Community,

I am attempting to clean up a Revit template file and am struggling trying to purge USED items. I would like to purge unused but it does not appear in the list because the particular arrowhead must be used somewhere in the template. I would like to use dynamo to find the instances of that arrowhead but this is a parameter value with in the text family and I am having trouble isolating just those linear dimensions that have that parameter value. Any help on this would be appreciated.

Thank you!