[gregw2]

I have cron jobs on my mac that update my hosts files (to block "addictive" sites in my case (not ads)). It doesn't really work.

Browsers cache and use outside DNS servers despite the hosts files. Chrome and sometimes Safari don't really honor the hosts files 100% of the time. Every once in a while I google around to try and restore my control, try to tweak my browser settings but I have yet to find anything that makes using hosts files bulletproof.

[mywittyname]

I think firewall rules would be your next line of defense. I'm not sure how configurable most home routers are though.