How to temporary limit web access to customer IP?

Hello! On some occasions, such as when a wordpress site is hacked, I need to block web access to a client's account. Suspending the account doesn't work because my client can't log in to fix the site. What I do is block everything but my customer's IP via htaccess and put that file as read only. I would like to know if there is a better way to do this, perhaps via an option in WHM. Thanks