What should i do with my sons moldy sneakers?

Throw them away. Talk to your son about if he ruins his shoes, he has to be responsible to save up and buy another pair. Also, teach him how to dry out his shoes the correct way. This will teach him responsibility. Plus if you continue to teach your son, he will be healthy, wealthy, and wise when he grows up. If you make your son rich, he will make you rich. You know what I mean.