That 8 gauge bare copper open wire is what some towns have used for fire alarm wire and the crooks aren't likely to get hurt cutting it down. In my city, the crooks have been taking copper pipes out of vacant houses and also Catalytic Converters off cars at dealerships.
I really don't go all out with hull cleaners on my boat. I've used Star-bright Hull cleaner to remove stains on my hull, but I won't use it on my deck because I'm afraid that it will eat out the caulking under my deck hardware and also under the gunwale strip. I've had leaks in my boat in the past and they're all fixed now and I aim to keep them that way. If I can get my boat cleaned well enough with soap and water and 409 Cleaner, I'll wax it a few times with a marine Teflon wax. Stay clear of any household cleansers with Oxalic Acid. It will remove the deep stains and dirt from Fiberglass, but it will also eat out caulking. I found that out the hard way. Try looking through this site's archives on bent masts and how they straightened them. I'm pretty sure that someone had brought this subject up just last year. Good luck with that Bob.
Joe