Sorry, just doesn’t work!
In theory it works, but in reality it doesn’t, because the quantity of copper sulphate which leeches out from the copper isn’t strong enough or in enough volume to have much effect on the moss.
Additionally, after as little as a few months the copper will tarnish and turn a greenish colour, this tarnish further reduces the release of copper sulphate to the point where moss will actually grow on the surface of the copper!
