Hundreds of years ago humans figure out how to combine sinew and glue and horn and wood in just such a way that you could shoot arrows over 500 yards through the air with a bow that weighs only 5 lbs.
If you want the silicone to stick to the pcv insulated wire, you can give it something to stick to. Smear a little silicone over the wire, then wrap some string tightly over the wire. Then cover with more silicone.