There's a lot of unnecessary comments to my answer which ideally should all be deleted IMO. So how do I do this or flag it for attention?
Click the "flag" link that you should find just below your answer, and you can write in the "other" field that the comments should be deleted. Or you can flag one of the comments and use the "other" option similarly. ("too chatty" could also work)
Before you do this, of course, I strongly suggest going through the comment thread to make sure that anything you might want to incorporate into your answer (or question), such as a clarification, has been taken care of.
You can just ask the other users involved to delete their comments, and then delete yours. This way it doesn't require outside intervention.