I had a conversation on expectations. At 10, they've most probably had some sort of sex ed in school. I took that opportunity to expand those conversations with my son about sexual conduct and how/what his role should be.
I explained that he will come across some websites that will show explicit material that's not meant for his age level. I told him if he had questions about that, to ask me and we'll talk about it. He then showed me on Wikipedia the definition of "reverse cowgirl" complete with a stick figure diagram.
Parental controls are great but it's things that fly under the radar that really needs addressing. The first time searching under "Kid Rock" can turn up very unexpected results, anywhere from the singer, The Lemonade Song to websites even I was shocked to see.
The best approach I used was to keep the computer in the living room, where I could see what he was doing. He had a strong sense to make sure he was only using sites appropriate while I was around. He never deleted browsing history and I did catch him once or twice.
I still feel that having conversations about certain issues is more beneficial than blocking something he shouldn't see. I let him know it's out there but not meant for him. At 21, he told me that porn is stupid and no one could actually live up to that kind of performance. I think he's a stand up kind of guy.