R..
Blisters? Cracking? Not sure what 'busting' means... If it IS cracking/severe peeling, you could try rubbing some bag balm into his feet, then putting some thick socks on top of that. have him sit for about 1/2 hour so it can soak in, then either rub it in the rest of the way or rinse it off. I would take him to his pedi. too, just to make sure he doesn't have a fungal infection or something. :)