I found a good way to solve this. You can create a button with a keyboard shortcut that does it.
To do this, right click the toolbar, click Customise quick access toolbar. Chose commands – All commands. Then find the Block Sender icon and click Add. Then OK.
The block sender icon is now on the Quick access toolbar, and will be actioned as ALT- with some digit: Mine was 7 as it’s the 7th item.
That allows you to junk a whole sequence of items just by repeatedly clicking Alt-.
