Hey Nd, if you do not want third party solutions there are ways you can try but manual work is more. Steps you can do:
1. Change DNS Service – DNS service is used for Domain Name resolution on internet. You can replace your DNS with OpenDns that will help you blocking. OpenDns has a large database of porno content that will automatically block out keywords and websites.
Opendns site for more info
2. You can manually list and block websites in your linux system by listing in your Host file. But you need to manually enter each site manually that you want to block.
3. You can use system firewall in windows system and set outgoing rules for different sites and block them by manually adding each to the rules.
As you can see we have listed 3 ways , but i prefer OpenDns as it is easier and will automate the process for you.
Thanks for visiting. Have a visit again.