I cannot remember who gave me this advice, but it really worked!!!
Put coins in a can and shake it before or as soon, as he starts to bark.
It worked the first time I tried it. Now all I have to do is put the can close to him and he stops. It took a couple of times for him to stop.
I know you said you've already tried it, but I was wondering how and what you did when you tried it?
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