How do you hide/remove default Local mail folders?

Hi,

I've been trying to figure out how to remove or hide the default Local 
Mail folders, such as Inbox, Sent, Unsent Messages, Templates, etc.,  so 
that only my folders are visible.  The folders just get re-created if I 
manually delete them.  I tried a few settings, such as:

user_pref("mail.identity.default.fcc_folder","");
user_pref("mail.identity.default.draft_folder","");
user_pref("mail.identity.default.stationery_folder","");
user_pref("mail.identity.default.overrideGlobal_Pref", true);
user_pref("mail.identity.default.use_custom_prefs", true);
etc..

None of these seem to do the trick.  Perhaps I should be editing the 
'mailnews.js' file instead of 'prefs.js'?  Any help would be appreciated..

Thanks,
s.hewi