Posted: 08/01/2014 at 01:13
I've used old cable, stripped to bare copper, wrapped around pots and twisted together where it meets. This seems to do the trick.
I don't think it's the width of copper, but just the substance itself which when wet seems to take on a small electrical charge.
I've found this works better with two lots of cable set about 1/4 inch apart so any persistent slugs will span the two and get a better shock!
A bit fiddly sometimes as it seems to slide down the cone shape of the pot but I've stuck mine on with silicone and when using fresh pots turned upside down overnight until it cures.