I rehab vintage Japanese porros for environmental education programs and have worked on roughly 100 pair, including some Binolux, but this is the first time I have run across this note in the bottom of the case for a Binolux 7x35, Light Weight, Coated Optics, with plastic eye pieces, so I'm guessing from the 1960s?:
Silicone Cloth is a well-treated polishing cloth saturated with silicone which has several special qualities. Silicone Cloth gives not only lustre to any optical lenses but also produces quite thin oil (Silicone Oil) on the surface of the lenses and it prevents them from diffused light-reflection. Glass, lenses and any optical instruments are always clean from dust when Silicone Cloth is used."
Wow. Clearly this idea never caught on, but did it have a germ of theory behind it? And the specificity of "diffused light" reflection? I'm sure our optics experts could weigh in on this.
The case had just the note, not the cloth, which I assume was saturated with silicone oil. The idea that something coated in oil would not attract dust also seems a bit quaint. But everyone is always looking for a marketing advantage. :-)