I bought my kids a PC and installed 12.04 (Unity) on it. The bottom line is, I want my children to use the computer unsupervised while I have confidence they cannot access anything inappropriate.

What I have looked at:

I was looking at Scrubit a tool which allows me configure my wifi router to block content and this solution would also protect my other PC and mobile devices. This may be overkill as I just want the solution to work on one PC.

I also did some Google searches and came across the application called Nanny (it seems to look the part). My experience of OSS is that the best solutions frequently never appear first on a Google search list and in this case I need to trust the methods therefore my question is very specific.

I want to leverage your knowledge and experience to understand “What is the best way to restrict adult content on 12.04 LTS” as this is important to me. It maybe a combination of things so please don't answer this question "try this or that", then give me some PPA unless you can share your experience of how good it is and of course if there are any contraints.

Thanks in advance