Hi pacome,
This is what you do:
Click on the "spectacles". This will bring up a list of all articles which you have kept for reading.
To Delete One - Right Click on it and choose "Remove Item"
To Delete Several: using Command plus Left Click to highlight all the individual items - then Right Click and select "Removes Items"
To Delete them ALL: Left Click on top one, then use the Keyboard combination Command plus A. This will highlight/select them all. Now Right Click anywhere on them and choose "Remove Items".
Apologies, Ashwin, you said all this above; but I'm just spelling it out to help the OP
@pacome, please post back.
Ian