I've been keeping and fragging zoanthids for more than 20 years and have never experienced any of the issues that you see people talking about in horror stories on the internet.
I've fragged colonies in just about every conceivable way.
I do take certain steps. I always wear eye protection, I now wear disposable gloves, and always keep my mouth shut when fragging them.
I also use tongs to pick them up whenever possible.
After I'm done I wash my hands with warm soapy water.
Just use basic common sense and you will be fine.