Read the last sentence you quoted above from AdSense help:
"...you cannot opt out of showing ads to users based on their previous interactions with the advertiser, such as visits to an advertiser's website."
Really, you have no control over it, and Google will track actions even on sites without AdSense. As I mentioned in my first post, just visiting a corporate site that uses Google Analytics was enough to have AdSense ads follow me around for that company for weeks.
You have no control over interest based ads, except to prevent visitors to your site from having their activities while on your site monitored.
My experience with the ads following me around was shocking. I have zero interest in the company and in its area of business, yet I saw hundreds of ads for that company for almost a month afterward, just because that site uses Analytics.