My boyfriends parents did this to one of their two dogs.
I met the dog before it had the "procedure" and the barking was a bit out of control... i guess...
I call the first week I had my dog "hell week". It was so hard to be consistant every second of the day. It was well worth it. I had to train myself more than I had to train my dog. now I have a dog who has no idea what people food is (no begging at the table) and actually listens to me. if I say drop she drops. if I say stay... she stays.
she recently has found her voice and I feel a quick "Psssssst!" does the trick. Well that and I never give her what she wants when she is barking.
again, I had to train myself. It takes time and it can be very frustrating but worth it in the end.
Their dog did not sound like a "squeek toy" I used to joke that it had "hooker voice" (a bit inappropriate? eep!) I joked that it sounded as if their dog was asking me if I had "a menthol, hun" :P it had a very raspy-like bark.
weird enough, its bark actually came back. huh