While reading this question on Ask Metafilter, in which the asker refers to some putative "Paul Reiser Effect," I remembered being in elementary school and how after you farted, you had to yell "Lou Rawls!" first, otherwise someone could hit you.
I have no fucking idea why.
I remember asking my dad "Why Lou Rawls?" when I was a kid, and while he hadn't heard of it, he speculated that Lou Rawls' rich baritone was some talisman.
Anyway, I think we just kind of misheard something or other and it caught on because elementary school boys are prone to adhering to arbitrary rules about farting enforced with violence.
I think the "Paul Reiser effect" is likely similar—something that sounded good at the moment, totally detached from any coherent meaning.