Maybe not what you are looking for, but on your webpage for Pocket, you can do "Bulk Edit" and delete. Select the pencil-like icon on the right of the top bar

Maybe not what you are looking for, but on your webpage for Pocket, you can do "Bulk Edit" and delete. Select the pencil-like icon on the right of the top bar (hover over it to see words "Bulk Edit"). Select the articles you want to delete, then select the trashcan to delete them. On the Kobo, you are limited to deleting one item at a time, unfortunately. So you bulk edit on the web, then sync your Kobo to remove the items.