Report Builder 3.0: Can you clear saved user credentials?

If a user checks Remember my Password in the Connect to Report Server dialog box when logging into Report Builder, is there a way to clear out those credentials?

We are launching Report Builder 3.0 from SSRS using ClickOnce, and we have a security concern. Since RB credentials are stored per windows user, if someone saves credentials, another person could log into SSRS in the browser, launch Report Builder, and be logged in using the saved credentials as the other user. 

I'd like to know how to clear the credentials if they are saved.  I've tried deleting the local app cache (C:\Users\<UserName>\AppData\Local\Apps\2.0), but that doesn't work.  It causes ClickOnce to reinstall Report Builder, but the credentials are still saved.

Thanks for any help.
Bob