Sorry, Perly, but it isn't "obvious" at all.  I mean, maybe you know
something I don't (LOL), but not every substance we put in our mouths
comes floating out our pores.  Life would be pretty messy if that were
true.

None.  Acyclovir works by interfering with the *replication process*
of the virus *in* the epithelial cells, not by attacking stray viruses
that happen to be standing around.  

After acyclovir is ingested it is processed into various subcomponent
materials which only work within herpes infected cells.  As the herpes
virus goes to replicate, it grabs one of the acyclovir subcomponent
enzymes and sticks it into place in the new DNA chain, but that
antiviral enzyme ends up acting as a terminator in the chain,
effectively stopping the DNA copying process, and replication is
aborted, leaving a broken virus.

Viruses that make it to the skin surface have already been replicated,
and can't replicate *on* the surface, so any acyclovir (or related
enzymes) there would have no effect.

Antiviral creams work to the extent that they can penetrate the outer
boundary of the epidermis, where they can be used (if needed) by the
underlying epithelials, but there is not a lot of evidence that they
do a lot of good.

(Thanks to Dr Sacks again, for learning me some more.)

Zero.

Nope.  Sorry.  But we know soap kills the virus, so maybe go eat a
bunch of soap until that comes out your pores.  Let us know how it
goes, okay?

Mike