How to block naughty websites on an iPhone?

Hi. I'm wondering if anyone knows how to hide apps on the iPhone or if there are any apps that will block "naughty" sites (or youtube vids) that are hidden apps? If it makes any differences, it's an iPhone 4S. Any suggestions would be great, as I've already set parental locks but I'm not sure any of them work for blocking bad sites, other than totally removing Safari and Youtube from the i-iPhone, which i don't want to do.
Thanks!

Added (1). To rephrase, in case I worded it a bit confusingly: are there such a thing as any hidden apps that will block "naughty" sites (or youtube vids)?

Impossible

There's no efficient way to do this. Sorry.

I don't know of any that will do that, but you can download phone spy apps to know what content is being viewed, and if it is naughty, go in and stop it from being viewed. Also, if AT&T is the provider you use for this 4S, then you can pay a couple more bucks a month (if you can afford to) to get AT&T Smart Controls, to use instead of the locks already in place.