Yes, I've read stories on other forums of people ending up in the hospital after boiling their rocks. Zoanthids/palythoas have a very potent toxin that will go in the air when boiled, and even if you don't think there's any on your rocks i'd still be concerned just in case.
The safest way to go would be to bleach them in a container outside. I did this with my rocks a while back. I found a specific method online that I used, don't remember it anymore though. It does take patience though, because the rocks need to be rinsed and soaked in clean water several times to remove all the bleach.
Definitely won't leave any life behind though... And rocks end up looking white and new.