A friend once told me they went together with the mother-in-law. After asking a few questions, the officer left them and went to the waiting area to talk to the mother-in-law. He came back a few minutes later and then approved them. This was a guy whose case was not "clean". He had previously been married to a crack addict USC who had withdrawn their petition at the interview when the interviewing officer suggested she withdraw the petition or the parole officer would be called since she had violated her parole and had an arrest warrant.
So I guess, it could have its pluses.