Larry, I recently did a Drop Cap for Q that used an image of people lined up in a queue. Tracing with the Shape Editor tool, just to retain the people but not the background, wasn't going to be a viable option, so I used the Mask/Erase background method.

This worked fairly well but some of the background was still retained and required further cleaning. I could see some dirty remnants of the background but against a white backdrop they weren't clear, thus my comment:

place a high contrast rectangle below this and then use the eraser tool to further remove unwanted background artifacts
In other words, it's not just a one step process if there's a lack of original contrast between foreground and backdrop. It may need two or three clean ups.