Force deletion of custom cookie

I have set a cookie in community builder (comprofiler.pho and user.php) for a member id which is set to expire at the end of a session. But, depending upon the browser preferences, it doesn't automatically expire.

Is there some code I can add somewhere, like the session.php (in the joomla library), which can force the removal of this cookie?

Any help would be appreciated.

Thanks.

Cookies delete automatically by the browser based off their lifetime so you shouldn't have to do anything. At any rate setting the cookie to empty deletes it. I can't help you with core edits so you're on your own in that regard.