HARI OM harshadsinh,
your point is absolutely valid. but from what i have understood, a few possibilities arise
1) we read that After Kadru licks someone and that individual accepts her touch with reverence, then the person cannot be killed by any weapon except burning by a sacred fire.
2) Hercules and Zeus notice that Sothadorina is emitting the same type of smell as Hercules had noticed on Planet Drako. so they feel that either kadru licked sothadorina or Kadru is impersonating Sothadorina.
3) later we see that Bijoymalana notices that Circes eyes turned green on one occasion
and one of the vrati notices Circe catching a mouse from the foliage and eating it. while the individual is hiding near Kronos’ House (probably Leto. someone correct me if I am wrong)
also there is never a mention of a similar smell coming from the original Circe or Bijonmalana
This probably means that the smell originates from Kadru impersonating Sothadorina and is not related to her licking of the individual.