This is my attempt to create a more sustainable version of the instrument.
Step 1: Materials and tools
This is put together from corrugated card from an old box, duct tape, and a short piece of PVC pipe.
The only tools I used were a craft knife, my trusty Leatherman, and a hacksaw (to cut the pipe to length).
Step 2: The parts
Two flaps duct-taped together made the main coil, and a third flap, cut in half, made the end-pieces.
The flaps were 17cm wide, and when taped together they were just under a metre long. For the sake of aesthetics, I made the end-pieces 17cm square as well.
The pipe, a scrap I found in a corner, was about 2½cm in diameter, and about 10cm long.
Step 3: Curl it up
To that end, I used the two flaps which had the corrugations at right-angles to the long dimension. I dragged the strip hard over the corner of the table to force it into a curl, like quilling, writ large.
Step 4: Fix the curve
I anchored the spiral in place with small pieces of duct tape. Not pretty, but it worked.
Step 5: The mouthpiece
For comfort's sake, I used my knife to chamfer the edges of the pipe.
I cut a suitable hole in the middle of the second end-piece, and then anchored the mouthpiece in place with more duct tape, then fitted it in place and fixed with... duct tape.