They are codes that you redeem, you receive the electronically. So if you wish to use a fake address, it's not going to affect your ability to redeem points for Amazon credit.
They do have a toolbar, but you don't have to install that. You can just use the search engine on their website, it's basically like Google search but it has paid listings inserted in the results. It's pretty easy to make out which ones are paid and to just skim over them.