Checking out orphans with -f

I am trying to write some scripts which do various things to a git repo and I have run into a issue where I think that git behavior with respect to orphan branches is potentially undesirable. If I type:

  git checkout --orphan a

I cannot easily abandon this state by simply typing:

  git check -f --orphan b

Is there a better simpler way to abandon a that I am not aware of? Am I miss understanding what -f is supposed to do? It seems like it should allow me to abandon the a orphan and continue to checkout the b orphan?

Thanks for any insights,

-Martin