DTV adds nothing to any DWG file at all: and by the same token you cannot permanently remove content with it either, this program is literally just a viewer with some queries and printing abilities.
That content is in the DWG file already: you either opened the wrong file, or you need to freeze layers to hide the content you don't wish to see after you open the file (DTV does not save DWG changes, it is like I said just a glorified file viewer), or move to layouts that already mask the content you don't wish to see.
That content is in the DWG file already: you either opened the wrong file, or you need to freeze layers to hide the content you don't wish to see after you open the file (DTV does not save DWG changes, it is like I said just a glorified file viewer), or move to layouts that already mask the content you don't wish to see.