I have tried this recipe for other insects with luck, but never with stink bugs. Might be worth a shot.
Not my recipe but one I found online.
Garden Insect Repellent
1 Quart Water
½ Cup Brewed Coffee
1 Tbs Dish Soap (Dawn, Palmolive, Cheap Store Brand, etc.)
1 Tbs Oil (Canola, Vegetable, etc.)...