How do I access the 'Shader' property of the Greyscale Effect?

When I add the Grayscale Effect at runtime to a camera the Shader property is removed from the component.

I can manually add this again by simply dragging the Grayscale Effect shader into the inspector but when I attempt to do this in code I have no idea how to access the components shader.

I have tried myGrayscaleComponent.Shader=Shader.Find("Greyscale") but that doesn't work.