My DD (14) gets a lot of comfort from holding and chewing a fidget toy. Her current favourite is this one: www.tinknstink.co.uk/chewigem-hexichew.html
She destroys these very quickly - they typically last around a week before I need to throw them away as they are crumbling and I worry about her swallowing small pieces.
I appreciate nothing is indestructible, but would appreciate any recommendations. I can't keep replacing these weekly. Thanks.