Good for you, I think simple things like this can only enhance and enrich a captives experience. I too use PVC, making simple mazes and challenging the snake to find its food. My Indigos are quite sight oriented, so they are not real skilled...

Using PVC pipes offers a good way for the indigos to seek shelter and thermoregulate, probably a simple way in captivity to imitate a burrow, which Indigos clearly use in the wild.