I would expect there is a ritual/practical expert whose role it is to do this, safely. And I would expect a rabbi to be able to speak about it without necessarily telling lay people all of the relevant details.

In any event, Rabbi SOl's word about it is good enough for me. I don't understand why people feel they can criticize traditions and practices they do not themselves claim. Seems to me one would need to understand it from the inside to know what's what.

~Susan