Clear duplicates

Here's the situation:

• I subscribed to a few planets (like planet-libre.org)
• I subscribed to a few blogs that put some of its articles (but not all of them) on some of those planets

Once in a while, I have duplicates : the article of the planet subscription and the one of the blog subscription.

I'm wondering if it's possible to think about a way to "clear" the displayed articles in those cases and to display only one of them (like the original one, not the copies on the planets).