Someone needs to teach the people at PetSmart. Salt. Need to get your dog to throw up, give them a bowl of salt. They'll keep licking until they throw up.
And, for those saying that the dog will just pass it - dogs can ingest larger objects than they can pass. We had a cocker spaniel that was awful for eating things she shouldn't (one was a "super ball" that was 2" in diameter) - each time, she got opened up because there was no way she was going to pass it.
Obviously, repeat performances are bad - it builds up scar tissue, opening your dog up like that.