Break the Matrix

Hello,
so I have read a lot and I mean a lot over the past months about Face Pulling, NCR, expanding the palat, etc.
I want to start the face pulling but there is one thing holding me back, I do not have a retainer where I can attach the bands. I never had braces and I really do not know where to get such a thing here in germany, as all of the doctors are very sceptic and not open to anything. I would not even know what to say. I am searching for an alternative. On Platos Website there was this picture under the retainer titled "Kate in Poland came up with this brilliant solution". What was this? Was it simply a blue mouthguard? How do I construct something like that?
I also saw Walrus method of Pulling with laces and a mouthguard, and thought that you could just construct it the way he did, and than tie the laces around the bolts. Is this possible?

I really am searching for something that I can do, or is there anything where I can order such a retainer or something similar? I can easily get the same hockey helmet and everything else from the site for 50 euros but this is the problem.

I hope you guys can help me.

Thank you