I thought you were joking. It doesn't matter if it's low risk, it's still a risk, and yes there's a low chance of HIV, but this is made difficult, because a lot of oral sex is accompanied by other forms of sex. If you don't know the person, don't have oral sex, or wrap it up. It sucks, but you should never encourage people to not practice safe sex.
I'm not alone on this, the CDC, US aids organization (aids.gov) and many other agencies recommend wrapping up for oral, unless your partner knows you are clean. There is enough HIV/aids enough already, don't increase your chances of getting it and spreading it when you don't have to.
http://www.cdc.gov/hiv/risk/behavior/oralsex.html
C'mon man, don't encourage people to have bad sex practices, even if it is safer.