Would you have a workbook that we could look at? (See this post for more info about sharing workbooks on the forums).
I manage the content of the KB that you linked, so I'd be curious to see where you are stuck. A couple of things in case you have missed them:
- The article you linked above contains a sample workbook on the right side of the screen (called Clear All Filters Example Workbook.twbx) it can be useful to view and test the end result
- We also have another article to clear actions: Clearing All Actions in a Dashboard with One Click | Tableau Software that could be useful. (To view the end result, move the video forward to 6min11).