Removing Mysterious BlockAndSurf Ads from Chrome

I recently had the pleasure(?) of cleaning a number of adware programs off a Windows 7 laptop, including BlockAndSurf, sometimes known as Block-N-Surf, Re-Markable, or a whole host of other names. I used the ever-helpful MalwareBytes Anti-Malware and newly-discovered Hitman Pro to purge most of the horribleness from the machine, but the BlockAndSurf ads still lingered on many pages even though there was no Chrome extension for it or any other auto-start entry. It turns out that BlockAndSurf infects Chrome in some deep way that requires a complete uninstallation (remove browsing preferences, history, everything) and hosing of the directories in which it kept program files. After I ripped out every trace of Chrome and re-installed it, the ads were finally gone.