I'm desperately trying to find a solution to this problem. There are a number of specific key words that I no longer wish to be able to search for on my iphone 4s. I have managed to achieve this on both my laptops using k9 web protection, which provides the option to ban certain keywords as well as URLS. Unfortunately the k9 iphone app doesn't offer this service, nor do any of the other apps I have come across. Is it really an impossibility? Why am I able to do this on my laptop but not my phone? Please help, any serious answers greatly appreciated.
Added (1). Thank you so much for your reply. Unfortunately I'm in no way a tech-savy individual so if you would be willing to explain your reply in more detail I would greatly appreciate it, especially the second option since I'm aware that jail-braking the iphone can lead to unwanted complications.