I tried the second way on a more complex figure. In your butterfly example you can fill one continuous area with the paintbuchet tool. That was not possible with my figure. I'm trying to group all filled areas to create the cut part. If this doesn't work I'll start looking at the paint-bucket tool tutorials you refer to in your tutorial.
Here is another Paint Bucket tutorial and it shows how to select multiple areas of a design. http://www.youtube.com/watch?v=B7l_C9IL ... sva3Fi8H4F
and it may be suitable for your project.