It all depends on the cashier. Some won't let it fly. Go to someone who looks like they would be willing to try. If it doesn't work one day that doesn't mean you can't try another day.
I'm assuming that merchandise cards will not work since rewards won't work.
I'm going to try on my way to my daughter's house. There aren't many OM's around here any more and I know the one by my house will hassle me for sure.