redrawing plot with transparent background in wx

I’m embedding a plot in a wxPython panel, and I’d like it to blend in as much as possible, i.e. the area outside the plot itself should be transparent. I can call figure.figurePatch.set_alpha(0.0) to do this under normal circumstances, but in this case I’m also trying to redraw the plot periodically in response to a background process. When I do this, figure.clear() clears the plot area, but not the axes and labels, so I end up with all of the old axes superimposed. Is there a way to completely erase the background before redrawing?