From what I have seen, only the pranarians dry fast. I study many of them that are public. Once you get to that level, it is a metaphysical practice, an inner spiritual subjective knowing, imo, it is no longer a group support issue, you either know what you are doing and you do it, or you don't know what your doing and you don't do it.
I dry fasted by accident many times, became so preoccupied with life I forgot to eat or drink, with zero ill effects, so i know it can be done.
To do it consciously, for me, involves more understanding.