You need root. The ad blockers work by adding entries to the "Hosts" file to black hole ad domain's.
The Ad free addon did not seem to work with user debug but i am sure you could have done it manually if you wanted.
The other option is to do network level blocking at your router with DD-WRT firmware for your router and Ad-block.
http://www.howtogeek.com/51477/how-to-r ... on-dd-wrt/
This will remove ad's for all systems without the use of browser add-ons