I don't know any. But opening a full-screen-sized window and closing it should do the same.
I think the problem is deeper than that -- GEM expects you to behave "properly", there's nothing like a fullscreen app concept, everything is expected to be inside the window with its redraw function etc.
PeP fights similar problems with his Conholio, he could tell you more but there's really no such thing as a clean solution...