Two facts to consider to provide an answer to your question:
1. When the Big Book was written and published, it was expected by the authors that you would NOT have a sponsor. So, the directions were actually written in such a way -- that the alcoholic that was going to take the Steps, as prescribed... would have no guidance and have no sponsor at all. They would be alone -- and only have the book.
It was expected -- that the person reading the book and following the directions in the book -- "had purchased the book by mail order" and had received the book in the mail.
By the time that the book was finally printed in April 1939, there were less than 100 sober alcoholics in all of AA. If you didn't live in Akron, or Cleveland, Ohio, or in New York, and by then, Philadelphia -- you wouldn't have had the luxury of having a sponsor. No meetings. No phone list. No local central office to call. And, not one other AA in the entire city that you lived it.
This fact alone -- blows away any theories about the Big Book and the 12 Steps, that "they must be done with a sponsor" and also blows away the theory that a person can not take the Steps without a sponsor or without another AA.
There is NO MENTION of having a sponsor in the Big Book. And, above is the reason why. It goes from "taking the Steps" yourself -- (front cover through the end of Chapter 6) and immediately ASSUMES that in Chapter 7... YOU will be the sober AA in your town that is now qualified to "BE" as sponsor to someone else.
The only requirement is:
a. "it must be another human being" which means, it can't be your dog, or a light bulb or door knob. "someone else" and "somebody" ~pg 72, Big Book.
b. ~pg 74 mentions suggestions on "who we might consider" and offers a variety of options.
c. Then, goes on to say, that, it can be postponed ONLY for one reason:
"Notwithstanding the great necessity for discussing ourselves with someone, it may be one is so situated that there is no suitable person available. If that is so, this step may be postponed, only, however, if we hold ourselves in complete readiness to go through with it at the first opportunity. We say this because we are very anxious that we talk to the right person. It is important that he be able to keep a confidence; that he fully understand and approve what we are driving at; that he will not try to change our plan. But we must not use this as a mere excuse to postpone."
d. it is important that the person we choose can
d-1. keep a confidence.
d-2. they fully understand and approve what we are driving at (which eliminates a drunk that's blacked-out sitting on a bus bench or park bench).
d-3. they will not try to change our plan.
2. The AA History: Particularly, in Cleveland, Ohio, (and also in Akron) the Catholic Clergy became concerned about the alcoholics "hearing confessions." So, the Catholic Church was at first against -- the AA's there -- until it could be demonstrated that the AA's would not be "hearing the confessions of their church members." Which is why you have particular mention of this on page ~74:
"Those of us belonging to a religious denomination which requires confession must, and of course, will want to go to the properly appointed authority whose duty it is to receive it. Though we have no religious connection, we may still do well to talk with someone ordained by an
Summary: According to the Big Book instructions, you can do your 5th with ANY HUMAN BEING... as long as they can: keep confidence, they understand and approve of what you're attempting to do -- and they won't try to change your mind or talk you out of it.