I'm a firm believer than Dinos are in every tank. Balance and stability is what keeps them in check, especially when it comes to nutrients. I have always beat them back (never eliminated them, but as far as they are no longer visible or harmful) with a combination of nutrient stability and UV. Some strains are more difficult than others.
I would cure the rocks in a tote or bin and add beneficial bacteria and food if you are considering external treatment, but the dinoflagellates will survive in the main display anyway.