Unfortunately stinky toys seem to stay stinky!
I have 3 stinkies at the moment.
Two of them I've had almost a year and they still REEK!
I have tried washing and washing - with all sorts. This may sound strange but the only thing that tended to kill the obnoxious odor for a short time, was strong mouth wash. Or toothpaste.
But the smell always comes back a short time later.
I even have one sitting in a bag of bi-carb in the hope it would leech the smell out. It's been in there for about 4 months and still STINKS. It didn't do anything.
I have 2 going to the dump very soon!