I'd agree with that, I'm no autistic kid expert but at some point every kid will be upset about something. Being upset is part of life, learning to deal with it also is. I wouldn't use anything that look like a battery to reinforce his habit, it might be alright for a while but he'll get his hands on a real one at some point and if he hasn't learned that it's a no go he'll chew on it / might swallow it