Stinky Feet

What do I do about Hudson's stinky feet!! I got Hud these shoes from stride rite that he LOVES... he doesn't have to wear socks with them (a good thing because he has an extreme case of sock-o-phobia) and they are more like a sneaker than crocks... all around the perfect thing for him. BUT, and this is a BIG BUT, they make his feet smell so bad! Seriously bad... like I can tell when he takes his shoes off in the car because the smell just about knocks me out, which is not a good thing when I'm driving. We usually just put down the windows and are the car out when his shoes were off, but today it was pouring rain and we had to suffer for 20 minutes on the way home. I can't convey how seriously bad this smell is. So, what do I do? Trash the shoes? I can't, he loves them! Wash them? The shoes don't stink away from his feet.... I'm at a loss... any suggestions??