Okay, so this is my favorite AO setup so far. Just selectively darkening the base color via a hsv2 node.

A higher second value in the Bias node produces a more subtle effect in this case. I imagine 1.0 would effectively mean no AO at all, but I haven't tested that.

Here's a before and after:

It seems quite effective at counteracting the SSS artifacts that one often see in tight spots and just generally making the render look crisper.

-- I'm not mad at you, just Westphalian.