The can with the pennies in had exactly the same effect on our Harry...
I too now just say no in a sharp voice, that normally stops him....
But if he's reached that point of frenzy (we have somebody living in our Close that Harry particularly detests!!
) that he won't stop - I have concealed (now I sound like a magician!!
) one of his Kong Air squeaker balls and I do one very loud, sharp, as-if-it's-about-to-die squeak on it - and he comes running....detested man forgotten about...woo hoo!!
Good luck!
Sally + Harry x