I don’t know how it goes in Germany or US, but here in Finland you have several kinds of hardware stores and the ones that offer broader range of more exotic goods (often in oversized packages) only deal with registered businesses, not private individuals. Like at one point I tried to check if I can find lubricating PTFE tape locally, but no I can not except through these retailers. Kinda hampers the average customers attempts at this kind of thing.
I’m guessing, perhaps incorrectly, that the situation might be same in Germany and at least other Northern European countries, but not so much in US. In practice with Germany’s history with chemical industry and also in speciality industries that have relevant interests (like optics and musical equipment mentioned above) I suspect you could find something that’s just the thing (or even superior) locally, but nobody has done (or else has been unable to do) the legwork of finding out what’s it called and who makes it.