A few months ago I wrote a tip about emptying the Recycle Bin to save space (http://blogs.msdn.com/b/johnguin/archive/2014/02/17/onenote-tip-empty-the-notebook-recycle-bin-to-save-space.aspx)
While that is valid, there are a couple of points that have been mentioned by readers since then that I want to share.
First, as pointed out by Chip at the original article, the Recycle Bin icon was under the Share tab for OneNote 2010. I need point out that you can get the free version of OneNote 2013 over at www.onenote.com if you want the new UI.
Also, some of the clients do not show the Recycle Bin at all. I got an email asking how to delete items in this case, and the answer is you don't really need to worry about it. After 60 days, the old items will get emptied automatically so you do not need to micromanage this little detail if you do not want to. If you want to see what is there, you can get the free Windows version of OneNote, though, and just check on things.
I hope this clears some of this up.
Questions, comments, concerns and criticisms always welcome,John