We are trying to make our own ETC chamber, but we are in trouble trying to waterproof the electrode holes. We tried plastic kit around it, rubbers with plastic kit, rubbers without plastic kit, parafilm.. but the chamber keeps leaking. The plastic kit does not seem to stick to the chamber. Has anyone encountered the same problem? Hope you can help me out. A photo of our setup is included, after several tries we ended with the parafilm (still not waterproof).