Does anyone know of a way I can reduce the jaggedness of these edges?
The Remesh modifier makes the mesh rather blocky, so a simple subdivide will not do as the jagged edges consist of too large of a group of polys.
What are you trying to accomplish by using the Remesh modifier here? That blocky result is pretty much the designed behavior for the Remesh modifier, so if that’s not what you want, you probably shouldn’t be using that modifier.
I was using a spiral to boolean a cut through the head, which left some aliasing artifacts of loose quads. Remesh gave them some volume and smoothed them out, but at the price of blockiness.
There’s no really good shortcut to cleaning up topology after a boolean cut. You might be better off just retopologizing.
I definitely would be, just looking for a quick and dirty fix before I plunge.
Have you tried with the Laplacian Smooth modifier?
I never used it, but it should be aimed to that.
paolo
That’s the problem with quick and dirty: it almost always ends up looking quick and dirty. 
Thanks sourvinos - but well, K Horseman puts it aptly.
So glad for BSurfaces.