Egg wash substitutes

I do a lot of baking and I don't let lack of ingredients stop me. I need an egg wash today for my pretzels and I am without eggs. This is what I found online:

• According to 'Artisan bread in five minutes a day,' using a cornstarch slurry.

"Using a fork, blend 1/2 teaspoon cornstarch with a small amount of water to form a paste. Add 1/2 cup water and whisk with the fork. Microwave or boil until mixture appears glassy, about 30 to 60 seconds on high. It will keep in the refrigerator for two weeks; discard if it has an off smell."

• soy milk or milk
• vegetable oil