Soy sauce works!
My new earwig trap is a smashing success! :D There's at least two of the darn things floating in my container, and there haven't been any new holes in my plants. Woot! I took an empty (large size) yogurt container and added soy sauce, veg oil and water to fill it up two thirds of the way. I put it out of the way next to my pot of green onions (they've only been eating on those and my cinnamon basil), and over the night the earwigs apparently went for it.