I'm surprised at the fact no one has mentioned flavoured dental dams, just Saran Wrap (which is an illusion of protection, not actual protection). I think Saran Wrap is a joke - it's either a dental dam or bare. I know several ladies in Vancouver who do safe-GFE and only provide them with that. Hell, the girl that I used to rent my incall out to wouldn't do DATY without one. I also knew a few Austrailian ladies who worked in brothels who are actually the ones who introduced me to them when I was up in Canada. They were
*required* to use them, along with condoms for oral (on you, the client), and condoms for sex (of course).
I carry flavoured dental dams for people who aren't experienced in prepping for DATO because if there is any fecal matter in the area, Hep A becomes a risk. Generally guys who want that service though know exactly how to clean and prep so I've only had to use them a handful of times and I've never had anyone complain about it, they're thin enough I'm the only one who can really tell they're there.
http://www.glydehealth.com/dams.html
These are the ones I like, and as I've said really it's a cold day in hell when I need to use one but they're nice to have on hand. I have never used them for DATY on me, but I had another woman who wanted me to so I did. They just taste like vanilla, and she could still feel everything.