As you may know Adsense TOS prohibits “excessive profanity”. But this rule is subjective and, honestly, a bit scary. What exactly is “excessive profanity”?
You’re right its very subjective. But a little profanity isn’t going to get you banned so you really shoudn’t worry if there’s a small amount in your whole site.
I guess its excessive when you have it on every single page of a very big website.
If you’re really worried about it then the only way forward is to make sure you have no profanity at all.
i am sure you can get away with it in just a few posts vs. if you have hundreds of posts on your whole site with NO profanity.
Don’t worry about how much you can get away with. Play it safe and don’t have anything that might even remotely be considered profane.
I would class excess profanity as using words that may cause offence when there’s no need for them to be there. For instance, if it’s used appropriately and in context it’s probably fine, however if you’re swear yourself blue as an Irish smurf, it’s probably not a good idea to publish it. Many sites have strong language, but just don’t go in excess with it, like many things in life… it should be in moderation (I don’t agree swearing should be eliminated at all costs). 
Well for instance one of my site has been removed from adsense simply because I was giving another view of a plane accident, where I didn’t pretend to be sad, so a lot of people bashed me for not going with the group. I guess some of those mother****ers complained directly to adsense in order to attack me, and it worked. Adsense removed my site (even if it was only one page that was causing problem of blasphemy) from its network.
Anyway, blasphemy is very dangerous term, because it is simply what most people would find offensing. So saying God doesn’t exist could be seen as blasphemy, as any statement not shared by the majority. Not scary to you? OK, you’re in the mould.