Jawill's comments and experience chime with mine. And I do find it ironic that the vitriol expressed here towards barebackers does not extend to OWOers. Your chances of contracting anything may be very low with either unprotected sex or unprotected oral, but it's never totally out of the question.
Here's the thing that most people seem to be unaware of: a girl can have the gonorrhea bacteria in her throat for weeks without being aware of it. And it can be in her throat without moving up to her mouth, so a mouth swab might not pick it up. Gonnorhea stays local. She can have a blood test, urine test, vaginal swabs, and it won't show up.
Your dick goes in, and bingo. Now YOU have it. And as Jawill says, it's nasty. If it were just a couple of days of mild pain and little bit of pus, you might think that's OK. But it's worse than that. It hurts like hell when you pee, the gunk that comes out of the end of your knob is foul smelling, and your balls will swell up like Buster Gonads in Viz. One big hit of antibiotics will get rid of it, but it can take days to get better. Trust me. You do NOT want to get this.
Like other guys here, I had years of OWO with no problem. But once is enough. Don't much like OW, but there's one big plus: you've already got the condom on, so those moments of futzing around in between a BJ and sex while you try and get the fucker on and risk a wilter, are no more. Yeay!