Sorry if I'm not providing all of the information but I am doing so intentionally because why we are trying to do this is not relevant.
We are essentially trying to isolate blocks with unique attribute values by erasing blocks with the same information in the tags from the drawing.
I am looking to erase blocks with duplicate attributes and it doesn't matter which one is kept. I tried your routine Lee Mac and it didn't appear to delete anything? Anyways hopefully this clarifies what I am looking for.