Try eating a couple bowls of chili washed down with a 6’er of Busch the night before you go. That will chase that stinky foot smell right out of them. Homemade febreeze.
Seriously though. Its easier to keep the stink out than it is to destink them. Make sure you hang them up when you’re done so the insides can dry out. To clean them, turn them inside out (except for the boots) and get after em with some warm water and a bit of dawn. Dry completely. Waders, particularly neoprene, always seem to stink a little though. Doesn’t seem to bother the fish any.