You know that is a good question. Viral shedding can happen before, after and during an outbreak so you can’t be absolutely certain when shedding is occurring. But my advice is to consider the lesion healed when new skin has replaced the previously broken skin. The same is true with both oral and genital herpes. It is not possible to know if virus is still present when the skin is still red. Virus is not usually present in saliva.
Asymptomatic viral shedding, by definition, occurs without symptoms so your desire to nail down exactly when it is safe and no virus is present, is not possible to know.