I would agree. The average web surfer doesn’t understand the nuts and bolts of the web well enough to care that the codes mean anything.
One thought; it could actually work in your favor to show the affiliate code (as part of the viewable link). For example, you might be talking about a specific deposit bonus for a site and then the user sees the link with the code placed in it. They might think that code is specific to getting the bonus you are talking about, not realizing they could just type in the URL of the site and get the same thing.