wife used to throw a dozen or more over the fence daily
So that's where they're all coming from!
During one warm damp summer evening, I once collected upwards of 500 snails & slugs from the garden, 2000+ over the course of a week. Made a noticeable difference for a couple of years. Released them in local woodland. Haven't done that for a few years now (even a slacker like me has better ways of spending their evenings).
An excellent way to keep slugs and snails to a minimum is to employ the services of hedgehogs. Many years ago we took in a rescue pair and it worked a treat but now we have veg beds protected by netting (to prevent local cats using it as a loo) so hedgehogs wouldn't have access either. Unfortunately, the hogs have long since gone.
Plain water did the trick, I didn't try salt water.
I've just tried using my hand stapler, containing 26/6 staples, on the recycled plastic joists and the staples all crumpled, barely denting the surface - hopeless. Even with stronger staples I wouldn't expect success. So plan A is out the window and I didn't have a plan B until...
Could you hammer in a nail, loop the conducting wire around that (next to the plastic joist) then bend the nail up wards to hold the wire in place. Then move on to the next place, hammer in a nail ....
I think you're onto something. Your idea has sparked Plan B which is to use small pan head stainless screws and wrap one turn of wire around each screw as I work my way along the beam. Only possible problem is that the s/s wire rope is very springy so could be difficult to hold in place whilst I tighten the screw. Other than that, I thought of using pan head screws with a washer and bending one edge of the washer slightly to accommodate the wire as I tighten the screw - won't have to wrap wire around screw if that works. I'm confident one of those methods will work. Don't know why I prefer screws to nails, always have. I'm fine with drilling a pilot hole for each screw too. As you can probably tell, I have plenty of time on my hands so a time-consuming method isn't much of an issue. I just want a long term solution.
Thanks to all for your thoughts, suggestions and experiences. Much appreciated.