I'm not certain what you mean by "etiquette" here. Most GFE ladies are perfectly fine with DATY though that has nothing to do with how safe it may or may not be. I love DATY and indulge with providers just about all the time.  Heck, my ATF likes it better than my ex wife did!

Is it safe? Nothing in the hobby is without risk including the possibility of std's from eating pussy. I don't really know what the consensus is I just know that I personally am OK with what I feel is minimal risk.  If you read the reviews here you will see that there are an awful lot of guys who feel the same way.  That being said we all need to hobby within our own comfort zone and I'm not suggesting that you should indulge in any activity that you don't feel comfortable with.

But since most adults already have oral HSV1 and that supposedly makes it harder to catch HSV2 orally I think it's pretty safe. Someone correct me if I'm wrong.

Re: DATY? risky or not?

I will DATY but only if the lady is squeaky clean.  

I rarely find ladies that are fresh enough to satisfy my insanely freakish need for extremely clean pussy, but when I do, OMG....  I love to indulge.  

I have it in my head (right, wrong, or indifferent) that if she passes my freshness test then my "risk" in much lower than normal.

I like to do it also and have read that is is low risk but not 100% safe. There are articles written about oral sex being a low risk activity, but what I fear the most is HIV. There is no turning back once you have it, or even an std, I would bet that most guys on this forum are married so you have to consider what you may give to your SO. As for me, I;m dropping it from my routine. I have asked for 69 and when she swung around I got a good whiff of some stale pussy, all I said then was lets fuck instead. I was not about to clean her pussy with my tongue. I also worry about who was just in there before me, so DATY is out from now on.