HSV-targeting antivirals like acyclovir lower the chances of transmission when taken regularly by an infected individual. They do nothing if taken by those not carrying the virus. Keeping them on hand accomplishes nothing.
From the page you link:
> If you have genital herpes, you will probably be somewhat less likely to infect your partner if you use antiviral medication for prevention. The medications used for this purpose include acyclovir, famciclovir and valaciclovir. They must be taken every day over a long period of time, though. Using them as a creme or ointment is not suitable.
So it's been a while since I had an HSV scare, but from my research at the time you definitely want to start antivirals as soon as possible after symptoms start(assuming you know since it doesn't always cause symptoms). You want to reduce the viral load and let your body catch up which limits the spread and reduces severity of future breakouts.
From the page you link:
> If you have genital herpes, you will probably be somewhat less likely to infect your partner if you use antiviral medication for prevention. The medications used for this purpose include acyclovir, famciclovir and valaciclovir. They must be taken every day over a long period of time, though. Using them as a creme or ointment is not suitable.