i don't know what kind of reels he used, maybe they didn't have metal bits in them
but it was something to think about just the same
some plastics become limp when warmed even with a hair dryer.
i used to take rigid sheets of plastic and warm them to make them form
who knows what plastic reels are made of, HOT water to rinse them, and a few raps on a towel and air dry always worked for me ...
i use metal reels for the most part, and always have more than i need ...