Not sure I fully understand your adjustments, or see how the performance would work. I understand the need to get permission from the deceased/family and the crematorium, and the obvious difficulties that will bring with it. But you must also be very clear in what you are asking them to do – what do you need? Do you need to build a glassmaking structure in the crematorium, or will you only need to capture the smoke from the chimney? How? And can you make glass from air (soul) that is captured this way (e.g. can you use still air to make glass?)? You may want to talk to some glass makers. The big famous one in Holland is Leerdam glass factory, but the others may be also of help to your research (the last one is in Amsterdam). I would suggest that you talk to them first so you know exactly what you need when talking to the crematorium or the family.