Boolean operations on GraphicsPath

... or how to get an outline of a Region?

I have two rather complex shapes. I want to 'subtract' one from the other.
Well I can easily do this with a Region class which provides such a functionality, but then I wouldn't be able to draw an outline (there's no DrawRegion method, only FilRegion). If I keep my shapes as graphicspaths I will be able to draw outlines of them but I cannot perform boolean operations with them (Union, Intersection, Subtraction).
Is there any escape route of this magic loop with .Net Framework's GDI+?

P.S. I know how to do this with WPF but I don't want to overload my project with additional references.