Is it possible ( or advisable) to allow open access to the new theme customizer for potential clients?

Question

I've been using the new theme customizer and it really has me thinking how awesome it would be to allow potential theme buyers/clients etc to play with the customizer for a demo theme (without being logged in). The customizer is located at :

..wp-admin/customize.php.

So what it would take would be to somehow allow open access to this URL but nothing else in the back end. I suppose there is probably a security issue with this but I thought I'd get a discussion going on it here in case it's possible to do this safely as I'm sure other people might have the same idea.

So the question is : is there any safe way to allow open access to a single page of the admin?