I highly doubt that herbtana can eradicate marine ich from your tank.
Marine ich has been studied by scientist for years. We know very well its life cycle and all of effective treatments. If hertana is so effective against marine ich, we should have many success stories by now, both from scientific community and as well marine hobby industry.
Herbtana by itself may boost fish immune system and in turn fight off marine ich. Even that (boosting of immune system), we don't have any prove.
Back to OP's question, from the description, hertana is a herb extraction, and its (ineffectiveness) killing ich, I would say its clam safe
I have a lot of expensive angel fish that's why I am very interested in QT procedure and are familiar with all the current protocols to QT fish for ich.