antiseptic mouthwash and STD transmission

[electronman]

Is the risk of STD transmission via unprotected oral sex affected by the use of an antiseptic mouth wash either before (for transmission from the giver to the receiver of oral sex) or after (for transmission from the receiver to the giver) oral sex.  There was a post on this forum from September 30, 2006 in which Dr. Hunter Handsfield reported:
"Topical antiseptics, including listerine, have not been studied for their effectiveness in STD prevention. The best guess, based on distant past experience with other antiseptics (from thw WW II era) suggests little effect.  Washing after sex can't hurt, but I doubt using listerine, alcohol, etc does not any difference beyond the minor benefit of soap and water."

Can someone kindly explain why the use of an antiseptic mouth was  would have little or no impact on oral transmission of STD?  I understand that viruses (HIV, HPV) might not be killed by an antiseptic mouth wash but would the load of other microorganisms be reduced in the oral cavity thus reducing transmission risk?  This seems counter to basic germ theory and to countless public health recommendations to wash your hands to reduce transmission of various infections (including the flu virus).  I know that we're talking about something other than handwashing but the logic still seems to apply to the current example.  Is it possible that antiseptic mouthwashes simply don't work to reduce the microbe levels? If that is so, why do dentists have patients rinse with an antiseptic mouthwash?  

[gracefromHHP]

infections aren't laying in your mouth after performing oral and working their way down into your body to infect you. It's the heat and friction of the sex act that transmits most of them.  So gargling after performing oral isn't going to protect you - already too late by the time it's over with  . As far as gargling prior to oral to protect a partner, well I'd hope that if you knew you had something you were properly treating it and not being intimate with anyone until after enough time had passed for the infection to be cleared.

cold and flu germs survive well on surfaces and are easily transmitted thru hand to oral/nasal/eye contact which is why we recommend hand washing.  

If you had more specific std's in mind, feel free to post more specific questions about them.  

grace