This is something I've worried about. Echo is a silicone fanatic and I honestly don't think it's breakable. Luckily, once the silicone is chewed she gets bored and looks for something else. My biggest concern is cords. I found a monitor cord she had chewed on just a couple days ago and this is concerning. I admit I have given her old cords (I work in IT and have a lot of spares), but I'm conflicted about it. I worry about reinforcing the behavior. On the other hand I also know in my heart of hearts this is just not something I'm going to be able to break her of. She chews the grips on my pens, scissors, ear plugs, headset when she can get to it (which is not very often cuz it's a really really nice headset), and anything else that is soft enough to destroy. I'm on my third mouse since I got her, because she chews up the wheel. I can never decide whether to give her throw aways which I know reinforces the behavior or try to completely discourage her from that material. She has every safe alternative under the sun, but NOTHING seems to substitute for buttons on a remote.
So I guess the only saving grace is once she's gotten through the rubbery part she is completely disinterested in what is underneath, because yeah, what is underneath is incredibly toxic for both humans and birds. Just google "computer recycling in China" and you will find entire villages that now have to have water trucked in, because their water table is so contaminated with these materials. I'm not sure I'm entirely comfortable with the path I have taken, which is to let her have her own substitutes, but I do keep a very close eye and so far all she cares about is destroying the silicone which is her birdie cocaine.
