Animal Abuse???

I have a 4 month old pitt that ha sbecome somewhat unruly since I have been leaving her at home to go to work. She barks incessantly whenever i get home late at night, so I manufactured a device that i had read about on the internet. it's a tin pan(very lightweight) that is attached to her collar to amplify the sounds of her bark. The only problem is that she is petrified of the tin pan. I put it on her for 10 mins. and she froze, stayed in the same position until I removed it from her neck. If i even pick up the pan, she runs away and hides. Am i missing something, is there some type of negative ociation with tin and dogs???? And should I continue to use it?