Google recommends that you use the same adsense account for multiple sites. My question is: how can I do this with two unrelated sites while using the category blocking feature? Currently, I have ad revenue optimized by blocking certain categories of ads from displaying on site #1, however some of these categories I may want displayed on site #2. How can I go about doing this? I've been looking for a way to block categories by site or channel, but I can't find one.
There isn't one. If you have two dramatically different sites, you need two adsense accounts - the only way to do that is with a business and personal account.