Child accessing web via privacy policy within apps

Trying to find out how to further block child from accessing the web. Parental controls are on; however, he's a smart one! He's figured out that many apps have privacy policies and links to websites which will allow him to access the web. The general blocking of Safari/Google/etc. doesn't block this. We have added specific sites to the iPad blocked sites as well as added a new router to block sites to his device. But, with each app, there are various sites that they use so the list is limitless. Is there a way to do a 'blanket' blocking of web access other than not having internet access (which renders the iPad almost useless)?