Re: Shore power line "sticky"
The rubber on most shore power electric cables is PVC.
When molded, they add compounds to 'help' with the 'flow' of the molten PVC in the molding/extrusion process .... mostly di-octylphtalate, etc. These sticky compounds that come to the surface of flexible PVC are soluble in light weight mineral oil (WD40, PB Blaster, kerosene, diesel oil, etc.)
Rx.: take a cloth rag, soak with PB, etc., coat/wipe the 'sticky' with the 'oil', let soak for a time, wipe the cable with a dry rag; .... may need to repeat but the longer you soak the better the removal. One to two years later, do it all over again, etc.