/3/ - 3DCG

How can I get a spiral curve to wrap around an object in blender?
More importantly, an object with some degree of complexity.

I've been using the shrinkwrap modifier with varying degrees of success.
In the example, I can get a spiral to wrap around simple shapes pretty well.
But in the second example, as soon as introduce different angles to the wrapped object, the spiral messes up completely.
Also in the second example is the type of curve/spiral I'm using.
I've tried all three different types of spiral, but none gives any better result than the other.

Any ideas?