How to make worn loose suede boots stand stiff again?

I have a pair of 1yr old suede knee-high boots. I've worn them so often that they've lost their stiffness and now they crumple around my ankles if I wear them with anything other than jeans stuffed inside to hold them up. Is there a product or method to get them to stand up by themselves again? If it helps, I live in Japan (Japan usually has a product for everything, but the closest I've found is 'Sock Glue')