MamaGus,
I have done both. I made a quilt w/ fusible about 15 years ago. It has been washed numerous times. It just so happens to be a favorite of the kids/dog. I outlined the fusible pieces w/ a machine zig zag stitch. The edges have begun to finally "roll up".
In the essence of time, if it won' t be washed, I think you'd be just fine to use fusible w/ an overlocking stitch.
HTH,