Bleach won't clean copper out of anything, but it shouldn't be a problem for even the plastic stuff if you throughly clean things with clean water.
IMO the idea of copper leeching into silicon aquarium seals and plastic components is a myth. Any amount that would be absorbed is so miniscule that it wouldn't have any discernable impact. A popular misconception is that reef tanks need to be copper free, but copper is a trace element found in NSW, it's just in such low amounts that conventional test kits won't read it.
As far as your fake coral, if it's porous, it could definitely have absorbed copper and may leech it. IME/IMO live rock and such can eventually be used again after it has been exposed to copper, as it will leech into the water and be removed with water changes over time. However, this process takes a long time. Depending on how deeply and how concentrated the copper is/was, it could take years.
I had a system that I treated with copper to knock out a velvet outbreak. It was a FOWLR system. After a couple years, I tried reintroducing inverts (crabs, dusters, etc) and was successfully able to keep them. What I didn't try were the very sensitive corals, anemones, etc.
Regardless, after you've cleaned everything up, I'd run cuprisorb or poly-filter in your filtration system for a few months to grab any trace amounts in case anything was released back into the water column.
