Sorry to not be able to really answer your actual question..except to answer a question with a question that is...
Effective for what? I'm guessing the repetitive thoughts or... brain fog or well, both would be nice, eh?
You're right in saying it probably doesn't matter what it gets called so much as figuring out something that works for it.

I have both, as it happens (though the BP has the greater negative impact on my functioning) and... a given thing can cause me greater or lesser amounts of anxiety. It doesn't constantly produce the same level (for me anyway), so.... sometimes I might think, "Oh, that's not really stressing me out so much right now", but damn if I'm not doing my little thing and/or thinking about The Thing anyway(!) Also, I tend to think of my hopelessly repetitive thoughts as part of the OCD. Racing thoughts are very different for me, and that one's my BP at work. Repetitive thoughts I can't let go, racing thoughts I can't hold on. Intrusive thoughts, well, they're just damn annoying whatever's causing them.

OR, maybe it is semantics...

In quickly reading up on:
http://psychcentral.com/disorders/ocd/
It talks about in most cases compulsions serving to alleviate anxiety, but also that the often the compulsions (and I assume obsessions as well) cause anxiety by their level of demandingness (word? lol). Or... intrusiveness? In that they are incredibly annoying, they are distressing (what we don't want and can't stop tends to be distressing, after all) and... that's a kind of anxiety, isn't it? Maybe it's not causing sweaty hands or whatever, but poor memory, confusion, poor concentration (brain fog??) can also indicate anxiety. So maybe it's just a semantics thing.

Just kind of thinking aloud here...