Chrome bookmarks have gone crazy

My brother tells me his Chrome bookmarks have 'gone crazy'.
He appears to have thousands of multiple entries for the same bookmark and when he does open one it's all wrong.
Some time ago I recommended he use Super Anti Spyware and he reckons the problem started after using that program.
I've suggested he resets Chrome, deletes his history and all the bookmarks and starts again.
I assume by doing that, Chrome won't re-load all the bookmarks from the cloud when he logs on to Google the next time he opens Chrome.
Is there anything that can be done prior to this last resort?