There's no really easy way short of replacing them. If they are like I think they are, there's a coat of rubber on at least part of the outside to help with grip. That rubber traps the moisture from your hands inside the gloves and keeps them from drying effectively. That's why they start to stink.
One thing you can do is when you are taking them off, let them come off inside out. Poke your fingers into them backwards, so that they are completely inside out. Let them dry that way after practice and games. You might even spray them with Lysol or something, but it might irritate your skin. You might also try washing them while they are inside out, but don't dry them in the dryer. It might cause the rubber to peel.
The inside out thing will help with the smell, but it's pretty inconvenient.