Cracking Office Documents using rainbow tables

Hi all,

I would like to check if anyone else has had any luck cracking password protected word documents and excel spreadsheets using rainbow tables. I am not refering to commercial rainbow tables such as ophcrack_office or PRTK. I was thinking that if we could somehow obtain the password hash located somewhere within the document itself, we could run that hash against something like rainbowcrack and then manually key in the password to gain access.. anyone care to share their experiences?

Bregan