In a paper I once wrote as an English major, I once proposed using "em" in the same manner as these kids use "yo". The advantage is that the pronunciation would mostly mirror "them" in speech ("When the patient comes in, have em fill out a form"). Of course the drawback was that there would be confusion with "him" and "them" (did he say "have 'im", "have em", or "have 'em"). I also proposed adapting "le" from Spanish/French for singular gender-neutral subjects ("whoever le is, le is the fastest driver I've seen").