I went through an exercise where I deliberately tried to block all porn from getting into my house. Not that I'm against porn, but I wanted to see if it was possible.
This included setting up a blocking proxy server using constantly updating blacklists, reconfiguring my DNS to use family friendly name resolution, forcing google and bing to always turn on safe search, etc. I tried to be as comprehensive as I could, and I am very IT literate.
I failed.
In order for this to work you have to whitelist every site you want to access - this is impossible to do, plus they would have to ban VPNs at the same time.
Twitter, Reddit, Facebook, duckduckgo were some of the most obvious routes to porn. I'm sure there a literally millions of others. Then there is the TOR and the dark web, and I definitely don't want my kids to go there.
This plan is stupid and impossible and should be scrapped immediately. Education and pro-active parenting is the key.
Also, if your children have smartphones then all bets are off.
Regardless, it's not the porn that I'm unduly worried about - it's the violence that I want stopped. I chose to try and block porn because that is what this government is obsessed with.